PHP

Target class [Controller] does not exist.

Route::get('/users', [UserController::class, 'index']);

Target class [SallyController] does not exist.

//In laravel 8 uncomment  protected $namespace='AppHttpControllers';

Target class [AppController] does not exist.

public function boot()
{
    ...

    Route::prefix('api')
        ->middleware('api')
        ->namespace('AppHttpControllers') // <---------
        ->group(base_path('routes/api.php'));

    ...
}

Target class [AppHttpControllersEmployeeController] does not exist.

[PagesController::class, 'index']