const code = ` <script> // ...your code... // define message handler const handleMessage = (m) => { console.log('received message', m) document.getElementById("messageText").innerHTML = m; }; // finally, configure iframe resizer options before importing the script window.iFrameResizer = { onMessage: handleMessage } </script> <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/iframe-resizer/4.3.6/iframeResizer.contentWindow.js"></script> <p id="messageText">loading...</p> `; return ( <iframe iframeResizer={{ log: true, onResized: ({ width, height }) => { console.log("iframe resized", width, height); }, }} className="border border-primary" srcDoc={code} message="my message" /> );