Larvel Passport test get access token

test.php

class PassportTest extends TestCase
{
    /** @test */
    public function unauthenticated_cannot_access_api_endpoint()
    {
        $response = $this->get('api/queue/list');
        $response->assertRedirect('/login');
    }

    /** @test */
    public function authenticated_can_access_endpoint()
    {
        $response = $this->requestAccessToken();
        $this->assertArrayHasKey('access_token', $response);

        $response = $this->get('api/queue/list', [
            'Authorization' => 'Bearer '. $response['access_token'],
            'Accept' => 'application/json',
            'Content-Type' => 'application/json',
        ]);
    }


    /**
     * @return array
     */
    private function requestAccessToken()
    {
        $client = new \Laravel\Passport\ClientRepository();
        $client = $client->createPersonalAccessClient(null, 'Foobar', config('app.url'));

        // Arrange
        $body = [
            'grant_type' => 'client_credentials',
            'client_id' => (string) $client->id,
            'client_secret' => $client->secret,
        ];

        return $this->post('/oauth/token', $body, ['Accept' => 'application/json'])->json();
    }
}