How can target a LIST , How to add attributes to the JSON

[beshoo]

Dear @xh3n1
Am testing the Rest API, and it works great.
The problem is how can I target a specific List.
and how can I add the attributes to the json?

try {
    $subscriberRequest = $client->request('POST', $base_uri . '/subscribers',
        [
            'headers' => [
                'Authorization' => 'Basic ' . $credentials,
                'Content-Type' => 'application/json',
            ],
            'json' => [
                'email' => 'restapi@example.com',
                'confirmed' => true,
                'blacklisted' => false,
                'html_email' => true,
                'disabled' => false,
            ],
        ]
    );
} catch (\GuzzleHttp\Exception\GuzzleException $e) {
}