JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//tinymce.cachefly.net/4.0/tinymce.min.js"></script>
 <textarea></textarea>

JavaScript

tinymce.init({
    selector: "textarea",
    setup: function(editor) {
      editor.addButton('button', {
        type: 'menubutton',
        text: 'button',
        icon: false,
        
          menu: [
         { text:'Paper Size', onclick: function()
            {
              editor.windowManager.open({
                title: 'Paper Size',
                width : 200,
                height : 100,
                body: [
{type: 'radio', name: 'letter', label: 'Letter'},
{type: 'radio', name: 'custom', label: 'Custom'},
                ],
                onsubmit: function(e) {  
            editor.insertContent('Letter: ' + e.data.letter);
            editor.insertContent('Custom: ' + e.data.custom);
                }
              });
            }
        } 
          ]    
          
     });
    },
toolbar: " button "
})