Overwrites GCal events title and description

appointments.php

<?php

add_filter( 'appointments_gcal_update_event', 'appointments_hooks_gcal_update_event', 10, 2 );
function appointments_hooks_gcal_update_event( $event, $appointment ) {
	$appointments = appointments();
	$gcal_api = $appointments->get_gcal_api();
	$event = $gcal_api->appointment_to_gcal_event( $appointment->ID );
	return $event;
}