How to set up a key event in GA4 for a form submission

The following Google Analytics Help article will guide you through tracking a form’s ‘thank you’ page as a key event.

Please be aware that if ‘Enhanced Measurements’ are enabled for your property, you may already be receiving form_submit events, and that following the steps for tracking the ‘thank you’ page will not interfere with the form_submit events because a different event name will be used.  Although having both systems is likely redundant, it’s possible the ‘thank you’ page tracking may indicate there are issues in how Enhanced Measurements are reporting the form submissions.