mepr-forward-old-ipn.php

<?php

function mepr_forward_old_ipn() {
    if ( ! isset( $_GET['option'] ) && $_GET['option'] != 'com_osmembership' || empty( $_POST ) ) {
        return;
    }

    $memberpress_ipn_url = 'https://www.site.com/mepr/notify/pja675-3wu/ipn'; // CHANGE THIS

    wp_remote_post( $memberpress_ipn_url, array( 'body' => stripslashes_deep( $_POST ), 'sslverify' => false ) );

   _e( 'Success', 'memberpress' );

   die();
}
add_action( 'init', 'mepr_forward_old_ipn' );