diff --git a/twitter.js b/twitter.js
index e6df503..6c392e6 100644
--- a/twitter.js
+++ b/twitter.js
@@ -1,21 +1,18 @@
-const crypto = require('crypto');
-const OAuth = require('oauth-1.0a');
-const Fetch = require('cross-fetch');
-const querystring = require('querystring');
-const Stream = require('./stream');
+const crypto = require("crypto");
+const OAuth = require("oauth-1.0a");
+const Fetch = require("cross-fetch");
+const querystring = require("querystring");
+const Stream = require("./stream");
 
-const getUrl = (subdomain, endpoint = '1.1') =>
+const getUrl = (subdomain, endpoint = "21.1") =>
   `https://${subdomain}.twitter.com/${endpoint}`;
 
 const createOauthClient = ({ key, secret }) => {
   const client = OAuth({
     consumer: { key, secret },
-    signature_method: 'HMAC-SHA1',
+    signature_method: "HMAC-SHA1",
     hash_function(baseString, key) {
-      return crypto
-        .createHmac('sha1', key)
-        .update(baseString)
-        .digest('base64');
+      return crypto.createHmac("sha1", key).update(baseString).digest("base64");
     },
   });
 
@@ -23,13 +20,13 @@ const createOauthClient = ({ key, secret }) => {
 };
 
 const defaults = {
-  subdomain: 'api',
+  subdomain: "api",
   consumer_key: null,
   consumer_secret: null,
   access_token_key: null,
   access_token_secret: null,
   bearer_token: null,
-  version: '1.1',
+  version: "1.1",
   extension: true,
 };
 
@@ -38,32 +35,32 @@ const defaults = {
 // It appears that JSON payloads don't need to be included in the signature,
 // because sending DMs works without signing the POST body
 const JSON_ENDPOINTS = [
-  'direct_messages/events/new',
-  'direct_messages/welcome_messages/new',
-  'direct_messages/welcome_messages/rules/new',
-  'media/metadata/create',
-  'collections/entries/curate',
+  "direct_messages/events/new",
+  "direct_messages/welcome_messages/new",
+  "direct_messages/welcome_messages/rules/new",
+  "media/metadata/create",
+  "collections/entries/curate",
 ];
 
 const baseHeaders = {
-  'Content-Type': 'application/json',
-  Accept: 'application/json',
+  "Content-Type": "application/json",
+  Accept: "application/json",
 };
 
 function percentEncode(string) {
   // From OAuth.prototype.percentEncode
   return string
-    .replace(/!/g, '%21')
-    .replace(/\*/g, '%2A')
-    .replace(/'/g, '%27')
-    .replace(/\(/g, '%28')
-    .replace(/\)/g, '%29');
+    .replace(/!/g, "%21")
+    .replace(/\*/g, "%2A")
+    .replace(/'/g, "%27")
+    .replace(/\(/g, "%28")
+    .replace(/\)/g, "%29");
 }
 
 class Twitter {
   constructor(options) {
     const config = Object.assign({}, defaults, options);
-    this.authType = config.bearer_token ? 'App' : 'User';
+    this.authType = config.bearer_token ? "App" : "User";
     this.client = createOauthClient({
       key: config.consumer_key,
       secret: config.consumer_secret,
@@ -75,7 +72,7 @@ class Twitter {
     };
 
     this.url = getUrl(config.subdomain, config.version);
-    this.oauth = getUrl(config.subdomain, 'oauth');
+    this.oauth = getUrl(config.subdomain, "oauth");
     this.config = config;
   }
 
@@ -89,19 +86,22 @@ class Twitter {
     const headers = response.headers; // TODO: see #44
     if (response.ok) {
       // Return empty response on 204 "No content", or Content-Length=0
-      if (response.status === 204 || response.headers.get('content-length') === '0')
+      if (
+        response.status === 204 ||
+        response.headers.get("content-length") === "0"
+      )
         return {
           _headers: headers,
         };
       // Otherwise, parse JSON response
-      return response.json().then(res => {
+      return response.json().then((res) => {
         res._headers = headers; // TODO: this creates an array-like object when it adds _headers to an array response
         return res;
       });
     } else {
       throw {
         _headers: headers,
-        ...await response.json(),
+        ...(await response.json()),
       };
     }
   }
@@ -133,16 +133,16 @@ class Twitter {
   async getBearerToken() {
     const headers = {
       Authorization:
-        'Basic ' +
+        "Basic " +
         Buffer.from(
-          this.config.consumer_key + ':' + this.config.consumer_secret,
-        ).toString('base64'),
-      'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
+          this.config.consumer_key + ":" + this.config.consumer_secret
+        ).toString("base64"),
+      "Content-Type": "application/x-www-form-urlencoded;charset=UTF-8",
     };
 
-    const results = await Fetch('https://api.twitter.com/oauth2/token', {
-      method: 'POST',
-      body: 'grant_type=client_credentials',
+    const results = await Fetch("https://api.twitter.com/oauth2/token", {
+      method: "POST",
+      body: "grant_type=client_credentials",
       headers,
     }).then(Twitter._handleResponse);
 
@@ -152,22 +152,21 @@ class Twitter {
   async getRequestToken(twitterCallbackUrl) {
     const requestData = {
       url: `${this.oauth}/request_token`,
-      method: 'POST',
+      method: "POST",
     };
 
     let parameters = {};
     if (twitterCallbackUrl) parameters = { oauth_callback: twitterCallbackUrl };
-    if (parameters) requestData.url += '?' + querystring.stringify(parameters);
+    if (parameters) requestData.url += "?" + querystring.stringify(parameters);
 
     const headers = this.client.toHeader(
-      this.client.authorize(requestData, {}),
+      this.client.authorize(requestData, {})
     );
 
     const results = await Fetch(requestData.url, {
-      method: 'POST',
+      method: "POST",
       headers: Object.assign({}, baseHeaders, headers),
-    })
-      .then(Twitter._handleResponseTextOrJson);
+    }).then(Twitter._handleResponseTextOrJson);
 
     return results;
   }
@@ -175,19 +174,22 @@ class Twitter {
   async getAccessToken(options) {
     const requestData = {
       url: `${this.oauth}/access_token`,
-      method: 'POST',
+      method: "POST",
     };
 
-    let parameters = { oauth_verifier: options.oauth_verifier, oauth_token: options.oauth_token };
-    if (parameters.oauth_verifier && parameters.oauth_token) requestData.url += '?' + querystring.stringify(parameters);
+    let parameters = {
+      oauth_verifier: options.oauth_verifier,
+      oauth_token: options.oauth_token,
+    };
+    if (parameters.oauth_verifier && parameters.oauth_token)
+      requestData.url += "?" + querystring.stringify(parameters);
 
-    const headers = this.client.toHeader( this.client.authorize(requestData) );
+    const headers = this.client.toHeader(this.client.authorize(requestData));
 
     const results = await Fetch(requestData.url, {
-      method: 'POST',
+      method: "POST",
       headers: Object.assign({}, baseHeaders, headers),
-    })
-      .then(Twitter._handleResponseTextOrJson);
+    }).then(Twitter._handleResponseTextOrJson);
 
     return results;
   }
@@ -202,17 +204,19 @@ class Twitter {
    */
   _makeRequest(method, resource, parameters) {
     const requestData = {
-      url: `${this.url}/${resource}${this.config.extension ? '.json' : ''}`,
+      url: `${this.url}/${resource}${
+        !this.config.extension || this.config.version == "2" ? "" : ".json"
+      }`,
       method,
     };
     if (parameters)
-      if (method === 'POST') requestData.data = parameters;
-      else requestData.url += '?' + querystring.stringify(parameters);
+      if (method === "POST") requestData.data = parameters;
+      else requestData.url += "?" + querystring.stringify(parameters);
 
     let headers = {};
-    if (this.authType === 'User') {
+    if (this.authType === "User") {
       headers = this.client.toHeader(
-        this.client.authorize(requestData, this.token),
+        this.client.authorize(requestData, this.token)
       );
     } else {
       headers = {
@@ -234,13 +238,12 @@ class Twitter {
    */
   get(resource, parameters) {
     const { requestData, headers } = this._makeRequest(
-      'GET',
+      "GET",
       resource,
-      parameters,
+      parameters
     );
 
-    return Fetch(requestData.url, { headers })
-      .then(Twitter._handleResponse);
+    return Fetch(requestData.url, { headers }).then(Twitter._handleResponse);
   }
 
   /**
@@ -253,9 +256,9 @@ class Twitter {
    */
   post(resource, body) {
     const { requestData, headers } = this._makeRequest(
-      'POST',
+      "POST",
       resource,
-      JSON_ENDPOINTS.includes(resource) ? null : body, // don't sign JSON bodies; only parameters
+      JSON_ENDPOINTS.includes(resource) ? null : body // don't sign JSON bodies; only parameters
     );
 
     const postHeaders = Object.assign({}, baseHeaders, headers);
@@ -263,15 +266,14 @@ class Twitter {
       body = JSON.stringify(body);
     } else {
       body = percentEncode(querystring.stringify(body));
-      postHeaders['Content-Type'] = 'application/x-www-form-urlencoded';
+      postHeaders["Content-Type"] = "application/json";
     }
 
     return Fetch(requestData.url, {
-      method: 'POST',
+      method: "POST",
       headers: postHeaders,
       body,
-    })
-      .then(Twitter._handleResponse);
+    }).then(Twitter._handleResponse);
   }
 
   /**
@@ -283,20 +285,19 @@ class Twitter {
    */
   put(resource, parameters, body) {
     const { requestData, headers } = this._makeRequest(
-      'PUT',
+      "PUT",
       resource,
-      parameters,
+      parameters
     );
 
     const putHeaders = Object.assign({}, baseHeaders, headers);
     body = JSON.stringify(body);
 
     return Fetch(requestData.url, {
-      method: 'PUT',
+      method: "PUT",
       headers: putHeaders,
       body,
-    })
-      .then(Twitter._handleResponse);
+    }).then(Twitter._handleResponse);
   }
 
   /**
@@ -306,49 +307,51 @@ class Twitter {
    * @returns {Stream}
    */
   stream(resource, parameters) {
-    if (this.authType !== 'User')
-      throw new Error('Streams require user context authentication');
+    if (this.authType !== "User")
+      throw new Error("Streams require user context authentication");
 
     const stream = new Stream();
 
     // POST the request, in order to accommodate long parameter lists, e.g.
     // up to 5000 ids for statuses/filter - https://developer.twitter.com/en/docs/tweets/filter-realtime/api-reference/post-statuses-filter
     const requestData = {
-      url: `${getUrl('stream')}/${resource}${this.config.extension ? '.json' : ''}`,
-      method: 'POST',
+      url: `${getUrl("stream")}/${resource}${
+        this.config.extension ? ".json" : ""
+      }`,
+      method: "POST",
     };
     if (parameters) requestData.data = parameters;
 
     const headers = this.client.toHeader(
-      this.client.authorize(requestData, this.token),
+      this.client.authorize(requestData, this.token)
     );
 
     const request = Fetch(requestData.url, {
-      method: 'POST',
+      method: "POST",
       headers: {
         ...headers,
-        'Content-Type': 'application/x-www-form-urlencoded',
+        "Content-Type": "application/x-www-form-urlencoded",
       },
       body: percentEncode(querystring.stringify(parameters)),
     });
 
     request
-      .then(response => {
+      .then((response) => {
         stream.destroy = this.stream.destroy = () => response.body.destroy();
 
         if (response.ok) {
-          stream.emit('start', response);
+          stream.emit("start", response);
         } else {
-          response._headers = response.headers;  // TODO: see #44 - could omit the line
-          stream.emit('error', response);
+          response._headers = response.headers; // TODO: see #44 - could omit the line
+          stream.emit("error", response);
         }
 
         response.body
-          .on('data', chunk => stream.parse(chunk))
-          .on('error', error => stream.emit('error', error))  // no point in adding the original response headers
-          .on('end', () => stream.emit('end', response));
+          .on("data", (chunk) => stream.parse(chunk))
+          .on("error", (error) => stream.emit("error", error)) // no point in adding the original response headers
+          .on("end", () => stream.emit("end", response));
       })
-      .catch(error => stream.emit('error', error));
+      .catch((error) => stream.emit("error", error));
 
     return stream;
   }