Redirect WooCommerce PayPal Standard To PMPro IPN Handler.

pmpro-ipn-woocommerce.php

 <?php
 // Redirect WooCommerce IPN Requests to PMPro IPN as well.
 function my_ipn_redirect() {
	if ( ! empty( $_REQUEST['wc-api'] ) && defined( 'PMPRO_DIR' ) ) {
		require_once( PMPRO_DIR . "/services/ipnhandler.php" );	
		exit;
	}
}
add_action('init', 'my_ipn_redirect');

If you are using WooCommerce and PMPro. You can set the IPN URL in PayPal to the WooCommerce URL and then install this code to make sure PMPro processes IPN requests as well.

This recipe is included in the blog post on "Redirect the PayPal IPN for PMPro to WooCommerce" at Paid Memberships Pro here: https://www.paidmembershipspro.com/redirect-the-paypal-ipn-for-pmpro-to-woocommerce/