<!DOCTYPE html>
<html>
<body onload="logoDegistir()">
<div class="top-logo">First div element with class="example".</div>
<div class="top-logo">Second div element with class="example".</div>
<p>Click the button to change the text of the first div element with class="example" (index 0).</p>
<button onclick="myFunction()">Try it</button>
<p><strong>Note:</strong> The getElementsByClassName() method is not supported in Internet Explorer 8 and earlier versions.</p>
<script>
function logoDegistir() {
var x = document.getElementsByClassName("top-logo");
x[0].innerHTML = "<a href='https://zehrapolat.com/'><img alt='Logo' class='logo1 logo-dark' style='max-height:40px;' src='http://zehrapolat.com/wp-content/uploads/2021/06/zehra-polat-siyah-logo.png'><img alt='Logo' class='logo1 logo-white' style='max-height:40px;' src='https://zehrapolat.com/wp-content/uploads/2020/08/zehra-polat-beyaz-logo.png'></a> ";
}
</script>
</body>
</html>
</code>
Try It https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_document_getelementsbyclassname
Second Application
<script>
function logoDegistir() {
var x = document.getElementsByClassName("logo");
x[0].innerHTML = "<a href='https://demircarrental.com/' class='navbar-brand py-0'><img src='http://demircarrental.com/wp-content/uploads/2021/11/DEMİRCAR-rental-logo-1.png' alt='Demir Car Rental'></a>";
var y = document.getElementsByClassName("d-md-block");
y[0].innerHTML = "<a href='https://demircarrental.com/' class='navbar-brand py-0'><img src='http://demircarrental.com/wp-content/uploads/2021/11/DEMİRCAR-rental-logo-beyaz.png' alt='Demir Car Rental'></a>";
}
</script>