How to use the leaky_paywall_new_subscriber action to do something with the new user data after they are added to the WordPress user table

leaky-paywall-third-party.php

<?php 

// use the leaky_paywall_new_subscriber action to do something with the new user data after they are added to the WordPress user table
add_action( 'leaky_paywall_new_subscriber', 'lp_add_new_user_to_third_party_api', 20, 5 );

function lp_add_new_user_to_third_party_api( $user_id, $email, $meta, $customer_id, $meta_args ) {

	// replace with the specific API data needed by your third party system (mailchimp, emma, etc.)
	$api_key = 'yourkeyhere';
	$url = 'https://www.yourapiurl.com/resourcepath?key=' . $api_key;

	// replace args with the data and format that is needed by your third party API
	$args = array(
		'method' => 'POST',
		'timeout' => 45,
		'redirection' => 5,
		'httpversion' => '1.0',
		'blocking' => true,
		'body' => json_encode( 
			array( 
				'email_address' => $email, 
			)
		),
		'cookies' => array()
	);

	// send data to third party API
	$response = wp_remote_post( $url, $args );

	// return the response so you can perform an action based on the result of the API call
	return $response;

}