Dynamic facebook app credentials for Laravel 5.1 socialite

We are trying to use dynamic facebook app credentials for Laravel 5.1 socialite.

config/services.php

'facebook' => [
    'client_id' => 'xxxx',
    'client_secret' => 'xxxx',
    'redirect' => 'http://ift.tt/1OcZF6B',
],

On my controller file:

public function getConnectFacebook()
{
    return Socialite::driver('facebook')->redirect();
}

public function getFacebookCallback()
{
    $user = Socialite::driver('facebook')->user();        
}

We tried to overwrite the facebook driver this way:

public function getConnectFacebook()
{
     Config::Set("services.facebook.client_id", "dynamic_app_id");
     Config::Set("services.facebook.client_secret", "dynamic_app_secret");
     Config::Set("services.facebook.redirect", "dynamic_app_redirect");        
     return Socialite::driver('facebook')->redirect();
}    

But it was not working. Could you please let me know how we can achieve this?

Thanks.

via Chebli Mohamed