https://www.rstcloud.com/rst/assets/js/rst-hubspot-forms.js

1(function () {
2	'use strict';
3
4	// HubSpot's embedded forms post a message on submit; there's no other
5	// hook available since the form itself lives inside an iframe.
6	window.addEventListener('message', function (event) {
7		if (event.data && event.data.type === 'hsFormCallback' && event.data.eventName === 'onFormSubmitted') {
8			if (typeof gtag === 'function') {
9				gtag('event', 'form_submit', {
10					form_id: event.data.id || '',
11					form_type: 'hubspot'
12				});
13			}
14		}
15	});
16})();