<!doctype html> <html lang="en"> <head> <script src="<?php echo $_SERVER["FRONT_URL"] ?>/iframe_api.js"></script> <script> window.addEventListener('load', () => { WA.ui.registerMenuCommand('test', 'customIframeMenu.html', {autoClose: true}); }) </script> </head> <body> <p>Add a custom menu</p> </body> </html>