JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdn.tinymce.com/4/tinymce.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<textarea>My content</textarea>
<a class='btn btn-primary copyTinyMCEToclip'>Click here to copy tinymce</a>
<input type='text' value='Input text'/>

JavaScript

tinymce.init({
            selector: 'textarea',
            height: 300,
            menubar: false           
            
        });
        
        
        $('.copyTinyMCEToclip')
            .on('click',
                function() {
                    tinyMCE.activeEditor.selection.select(tinyMCE.activeEditor.getBody());
                    document.execCommand("copy");
                    $(this).text('copied');
                });