Actually I want, I declare a link in javascript. And copy the link using a button.
I'm trying this. But it's showing error.
$(document).ready(function() {
      $("#copy-button").click(function() {
        var copyLink = "https://stackoverflow.com/";
        copyLink .select();
        document.execCommand('copy');
      });
    });  body {
      padding: 20px;
    } <script>  src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
    <button type="button" id="copy-button" class="btn btn-lg btn-primary btn-block"> <span class="fa fa-copy"> </span> Copy </button>I'm trying this, but not work : Copy to clipboard with Rails and Javascript via a link
 
    