Woocommerce_subscription when a payment is made on a subscription

subscription-payment-complete.php

/*
 * woocommerce_subscription_payment_complete action hook
 * Triggered when a payment is made on a subscription
 * @param $subscription
*/

add_action( 'woocommerce_subscription_payment_complete', 'update_user', 10, 1 );

function update_user($subscription) {
	
		// Getting the user ID from the current subscription object
		$user_id = get_post_meta($subscription->ID, '_customer_user', true);
		
		// add user meta when user_type not defined
		$user_type = get_user_meta($user_id, 'user_plan_type' , false);

		update_user_meta( $user_id, 'user_plan_type' , 'pro' );

}