Adds a custom field to the event details sent to Zapier through Event Automator

tec_automator_event_add_custom_field.php

/**
 * Adds a custom field to the event details sent to Zapier through Event Automator.
 * Replace %%CUSTOMFIELD%% with your field name.
 *
 * @since 1.0.0
 *
 * @param array<string|mixed> An array of event details.
 * @param WP_Post An instance of the event WP_Post object.
 */
function tec_automator_event_add_custom_field( array $next_event, WP_Post $event ) {
	$custom_field = get_post_meta( $event->ID, '%%CUSTOMFIELD%%', true );
	if ( ! $custom_field ) {
		return $next_event;
	}

	$next_event['%%CUSTOMFIELD%%'] = $custom_field;

	return $next_event;
}

add_filter( 'tec_automator_map_event_details', 'tec_automator_event_add_custom_field', 10, 2 );