Route Method Does not exist

I am trying to create a route but I am getting error .Method Illuminate\Routing\Route::get does not exist.

Route::get('/', function () {
    $url = parse_url(URL::all());
    $domain = explode('.', $url['host']);
    $subdomain = $domain[0];
    $name = DB::table('users')->where('name', $subdomain)->get();
    dd($name); 
    // write the rest of your code.
});

unable to find this error

via Chebli Mohamed