'providers' => [
        EcPhp\LaravelCas\Providers\AppServiceProvider::class,
    ],

    'guards' => [
        'laravel-cas' => [
            'driver' => 'laravel-cas',
            'provider' => 'laravel-cas',
        ],
    ],

    'providers' => [
        'laravel-cas' => [
            'driver' => 'laravel-cas',
        ],
    ],

    protected $middlewareGroups = [
        'web' => [
            \EcPhp\LaravelCas\Middleware\CasAuthenticator::class
        ],
        ...
    ];

    <?php

    declare(strict_types=1);

    use Illuminate\Contracts\Foundation\Application;
    use Psr\Http\Client\ClientInterface;
    use GuzzleHttp\Client;
    use loophp\psr17\Psr17Interface;
    use Nyholm\Psr7\Factory\Psr17Factory;
    use loophp\psr17\Psr17;

    public function register(): void
    {
        $this->app->bind(
            ClientInterface::class,
            function(Application $app): ClientInterface {
                //or whatever client you want
               return new Client();
            }
        );
        $this->app->bind(
            Psr17Interface::class,
            function(Application $app): Psr17Interface {
                $psr17Factory = new Psr17Factory();

                //or whatever psr17 you want
                return new Psr17(
                    $psr17Factory,
                    $psr17Factory,
                    $psr17Factory,
                    $psr17Factory,
                    $psr17Factory,
                    $psr17Factory
                );
            }
        );
    }