Adds extra checkout data to the Zapier Add On's after_checkout_data trigger payload.

pmpro-customizations.php

<?php

/**
 * This recipe adds extra checkout data to the Zapier Add On's after_checkout_data trigger payload.
 *
 * It is intended for use with the Zapier Integration Add On:
 * https://www.paidmembershipspro.com/add-ons/pmpro-zapier/
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

function mypmproz_after_checkout_data($data, $user_id, $level, $order ) {
	// fetch the additional register helper values from meta
	$field1 = get_user_meta($user_id, 'NAME_OF_CUSTOM_FIELD', true);
	$field2 = get_user_meta($user_id, 'NAME_OF_SECOND_CUSTOM_FIELD', true);

	// add them to the $data payload
	$data['field1'] = $field1;
	$data['field2'] = $field2;

	// return modified payload
	return $data;
}
add_filters( 'pmproz_after_checkout_data', 'mypmproz_after_checkout_data', 10, 4 );