Heroku deploy on Laravel 8 app

Im getting an error when trying to deploy my Laravel app with Heroku, the error reads:

In Auth.php line 56 In order to use the Auth::routes() method, please install the laravel/ui package.

The composer require laravel/ui has been introduced and the current version running is this: "laravel/ui": "^3.1", however I am using this in my web routes:

Auth::routes([
    'verify' => true,
    'register' => false
]);

Did I implemented this code wrong? I used it because Im not open to receiving registered users at the moment, if one wanted to access those routes a 404 is shown. What can I do to make this better? Thanks!

Edit: Is there a command to get information about a package's version?