route /author/{username} in laravel note work

Hi i call this url http://127.0.0.1:8000/author/Tohidda and i see 404 not found error. i use this route but not work!...my route and controlelr is

  Route::get('/author/{username}','UserController@author')->name('dashboard.author');
public function author(User $user , Course $course,$username)
{
    $courses = Learning::with('course')->take(1)->latest()->get();
    $categories = Category::where('parent','0')->get();
    return view('Home.dashboard.author',compact('categories','user','courses','course','favorites'));
}

note:Tohidda my username in users table

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