When i visit to my.site/api/genre/slug-name

In route/api.php:

Route::prefix('genre')->group(function () {
    Route::get('/{slug}', [FilmController::class,'getFilmByGenre'])->name('api_genre_film');
});

In getFilmByGenre:

public function getFilmByGenre(Request $request, string $slug)
{
    dd($slug, $request->slug, $request->get("slug")); // "slug-name" - "slug-name" - null
}

Can anyone please explain to me the difference when using $slug, $request->slug and $request->get("slug")?

I’m using laravel 10.x. Thanks for your help!