<?php session_start(); require __DIR__ . '/../vendor/autoload.php'; $options = ['clientId' => '[consumer_key]', 'redirectUri' => '[redirect_uri]']; $provider = new rmartignoni\OAuth2\Client\Provider\Yahoo($options); $authorizationUrl = $provider->getAuthorizationUrl(); $_SESSION['oauth2state'] = $provider->getState(); header('Location: ' . $authorizationUrl);