Laravel 5.8: Interface is not instantiable - php

Question

I know that this question was asked so many times, but none of answers helped me.
I'm getting exception in Laravel 5.8:
Target [App\Repositories\Category\CategoryRepositoryInterface] is not instantiable while building [App\Http\Controllers\Admin\CategoryController, App\Services\CategoryServices].
What I've done without success:
Register App\Providers\RepositoryServiceProvider in providers
Structure:
app
- Repositories
- CategoryRepository.php
- CategoryRepositoryInterface.php
- Models
- CategoryModel.php
- Providers
- RepositoryServiceProvider.php
- Services
- CategoryService.php
CategoryRepositoryInterface.php:
<?php
namespace App\Repositories\Category;
interface CategoryRepositoryInterface
{
public function show();
}
CategoryRepository.php:
<?php
namespace App\Repositories\Category;
use App\Models\CategoryModel;
// use Illuminate\Support\Facades\DB;
use App\Repositories\Category\CategoryRepositoryInterface;
class CategoryRepository implements CategoryRepositoryInterface
{
const TABLE = 'category';
private $model;
public function __construct()
{
$this->model = new CategoryModel();
}
public function show()
{
return $this->model->all();
}
}
RepositoryServiceProvider.php:
<?php
namespace App\Providers;
use App\Repositories\Category\CategoryRepository;
use App\Repositories\Category\CategoryRepositoryInterface;
use Illuminate\Support\ServiceProvider;
class RepositoryServiceProvider extends ServiceProvider
{
public function boot() {}
public function register()
{
$this->app->singleton(CategoryRepositoryInterface::class, CategoryRepository::class);
}
}
CategoryController.php:
class CategoryController extends Controller
{
private $categoryServices;
function __construct(categoryServices $categoryServices)
{
$this->categoryServices = $categoryServices;
// dd($categoryServices);
}
public function index()
{
try {
$category = $this->categoryServices->index();
return view('AdminStore.pages.categorys.cate_list', compact('category'));
} catch (\Exception $e) {
abort('500');
}
}
composer.json:
"autoload": {
"psr-4": {
"App\\": "app/",
"App\\Models\\": "app/Models/",
"App\\Repositories\\": "app/Repositories/"
},