This package provides Teamleader OAuth 2.0 support for the PHP League's OAuth 2.0 Client.
composer require nascom/oauth2-teamleader
See the League documentation. This package provides a Teamleader specific provider you can use instead of the generic one.
$provider = new Nascom\OAuth2\Client\Provider\Teamleader([
'clientId' => 'your-client-id',
'clientSecret' => 'your-client-secret',
'redirectUri' => 'https://example.com/your-redirect-url',
]);