Mage2\System\Models\Configuration::getConfiguration PHP Method

    public static function getConfiguration($key)
    {
        $model = new static();
        $row = $model->where('configuration_key', '=', $key)->first();
        if ($row != null) {
            return $row->configuration_value;
        }
    }

 /**
  * Show the form for creating a new user addresses.
  *
  * @return \Illuminate\Http\Response
  */
 public function create()
 {
     $user = Auth::user();
     $countries = Country::all();
     $defaultCountry = Configuration::getConfiguration('mage2_address_default_country');
     return view('address.my-account.create-address')->with('user', $user)->with('countries', $countries)->with('defaultCountry', $defaultCountry);
 }