Sending an OAuth token withing a request is one of the authentication ways. If you need a small amount of tokens, you can create them manually at Personal Access Tokens page. Click to Generate new token, copy the token string and:

$token = new Milo\Github\OAuth\Token('.s.e.c.r.e.t.');

Following chapter describes a token obtaining by OAuth web flow.

Class Milo\Github\OAuth\Login helps you. Workflow to obtain the token in a short:

1. you redirect user to GitHub web page
2. user allows access for your application
3. after agree-click, user is redirected back to your application with a code in URL
4. you get the code and send a POST request to obtain a token
5. you have the token

Let's obtain the token. At first, register your application at GitHub web site:

Account Settings
    -> Developer settings
        -> OAuth Apps
            (New OAuth App)

There you get a $clientId and $clientSecret which you will need. Read about token scopes and let's code:

use Milo\Github;

session_start();

$config = new Github\OAuth\Configuration($clientId, $clientSecret, ['user', 'repo']);
$storage = new Github\Storages\SessionStorage;  # default naive implementation
$login = new Github\OAuth\Login($config, $storage);

# Your application URL
$appUrl = 'https://my.application.tld/index.php';

# Token obtaining
if ($login->hasToken()) {
    $token = $login->getToken();

} else {
    if (isset($_GET['back'])) {
        $token = $login->obtainToken($_GET['code'], $_GET['state']);
        header("Location: $appUrl");  # drop the 'code' and 'state' from URL
        die();

    } else {
        # Performs redirect to Github page
        $login->askPermissions("$appUrl?back=1");
    }
}

Example should be pretty straightforward but few notes:

• Login::askPermissions() performs the HTTP redirection and dies. If you wish, pass a callback as a 2nd argument and make redirection by your own. And don't forget to die().

• Login class needs session to store a security information and the token. There is used the Milo\Github\Storages\SessionStorage class which is a very naive implementation. Implement your own storage by ISessionStorage if you wish.

• The token is stored in a session storage. Drop it by Login::dropToken() if you wish.

Once you have a token, pass it to API. It will be used every GitHub API request.

$api = new Milo\Github\Api;
$api->setToken($token);