<?php require 'yo.php'; $user = $_POST['user']; // Get an API Key at dev.justyo.co $apiKey = '97bc8528-4e7b-8935-5dff-1f5d5c615749'; // Instanciate $yo = new Yo($apiKey); // Send a Yo to all your subscribers $yo->all(); // Send a Yo to one user $yo->user($user); // Get number of subscribers $count = $yo->subscribers(); // returns an int or false