Track HubSpot form submissions in GA4 (using Google Tag Manager)

1<script type="text/javascript">
2  window.addEventListener("message", function(event) {
3    if(event.data.type === 'hsFormCallback' && event.data.eventName === 'onFormSubmitted') {
4      window.dataLayer.push({
5        'event': 'hubspot-form-submit',
6        'hs-form-guid': event.data.id
7      });
8    }
9  });
10</script>