Redirect membr back to Addon Package purchased after checkout.

pmpro-addon-package-confirmation-url.php

<?php
/**
 * Redirect member back to Addon Packages page after checkout.
 *
 * 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 my_pmpro_addon_package_confirmation_url( $url, $user_id, $level ) {
	// Let's only do this if Addon Packages is active and a package id is passed.
	if ( function_exists( 'pmproap_hasAccess' ) && isset( $_REQUEST['ap'] ) && ! empty( $_REQUEST['ap'] ) ) {
		$ap = get_post( $_REQUEST['ap'] );
		if ( $ap ) {
			$url = get_permalink( $ap->ID );
		}
	}
	return $url;
}
add_filter( 'pmpro_confirmation_url', 'my_pmpro_addon_package_confirmation_url', 10, 3 );

This recipe works for on-site payment gateways and additional code may be required if you are using off-site payment gateways, e.g. Stripe Checkout, PayFast, Paystack, or CCBill.

If you are using an off-site gateway please also add the following recipe
https://gist.github.com/andrewlimaza/eddc8ba56dd89aee6b32dd85391271d8