Auth::routes(['register' => false]); not working in laravel 8

You could try this it's work for me. Add these routes just below the Auth::routes() to override the default registration routes. Any request to the /register route will redirect to the baseUrl.

Route::match(['get', 'post'], 'register', function(){
return redirect('/');
});

To disable registration in Laravel 8, remove the line Features::registration() or comment out the Feature in the app/config/fortify.php file

'features' => [
    // Features::registration(),
    Features::resetPasswords(),
    // Features::emailVerification(),
    Features::updateProfileInformation(),
    Features::updatePasswords(),
     Features::twoFactorAuthentication([
         'confirmPassword' => true,
     ]),
],

For Laravel Breeze. Just remove or comment this lines in routes/auth.php

Route::get('/register', [RegisteredUserController::class, 'create'])
            ->middleware('guest')
            ->name('register');

Route::post('/register', [RegisteredUserController::class, 'store'])
                ->middleware('guest');

Add this to your route

Route::match(['get', 'post'], 'register', function () {
    abort(404);
});