JS to listen for when the details form is submitted in the calendar.

appointment-conversion-wrapper.php

<?php 

add_action( 'enqueue_groundhogg_calendar_scripts', function (){
	// language=javascript
	$script = 'document.addEventListener("submit", function(event) {
  		// Check if the submitted element is a form with the specific class name
  		if (event.target.matches("form.details-form")) {
    			// Do GA stuff
  		}
	});';
	
	wp_add_inline_script( 'groundhogg-appointments-frontend', $script );
} );