AppServiceProvider.php

<?php

namespace App\Providers;

use App\OAuth\Provider;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        $this->extendSocialite();
        
        //
    }
    

    private function extendSocialite()
    {
        $socialite = $this->app->make(\Laravel\Socialite\Contracts\Factory::class);
        
        $socialite->extend('provider', function ($app) use ($socialite) {
                $config = $app['config']['services.provider'];
                return $socialite->buildProvider(Provider::class, $config);
            }
        );
    }
}