Updates the payment description in Stripe when purchasing a subscription using Stripe Checkout.

my_pmpro_stripe_checkout_session_parameters_subscription_description.php

<?php

/**
 * 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.
 */

// Copy from below this line

/**
 * Updates the payment description in Stripe when purchasing a subscription using Stripe Checkout.
 */
function my_pmpro_stripe_checkout_session_parameters_subscription_description( $checkout_session_params, $morder ) {
	if ( $checkout_session_params['mode'] === 'subscription' ) {
		$checkout_session_params['subscription_data']['description'] = $morder->membership_level->name;
	} else {
		$checkout_session_params['payment_intent_data']['description'] = $morder->membership_level->name;
	}
	return $checkout_session_params;
}
add_filter( 'pmpro_stripe_checkout_session_parameters', 'my_pmpro_stripe_checkout_session_parameters_subscription_description', 10, 2 );