Let's add the French language.

• Create a new file fr.json in the fr folder in the Wwwroot/../assets/lang folder and copy the en.json file code in this file.
• Now you need to add the language in the wwwroot/../assets/js/app.js file. In the function setLanguage add the "else if" condition as below code and make sure to add the french.jpg file in the wwwroot/../assets/images/flags folder.

  else if(lang=='fr') {
      document.getElementById("header-lang-img").src = "../../assets/images/flags/french.jpg";
  }

• You can simply use key attributes in the HTML tag to convert the language text. Example: <div key="t-title">This is title.</div>

• Add the below dropdown in the wwwroot/backend/partials/topbar.html file in the language dropdown.

  <!-- item-->
  <a href="javascript:void(0);" class="dropdown-item notify-item language" data-lang="sp" title="Spanish">
      <img src="../../assets/images/flags/french.jpg" alt="user-image" class="me-2 rounded" height="18">
      <span class="align-middle">French</span>
  </a>