comment resoudre le probleme de cors qui sont absents dans la requette provenant du backend de laravel 100% en php ?

To resolve CORS (Cross-Origin Resource Sharing) issues in a 100% PHP Laravel backend, follow these steps:

Understand CORS: CORS is a security feature implemented by web browsers to restrict access to resources on a different domain, protocol, or port than the one that served the request. Laravel is a PHP framework, and CORS issues may arise when making requests from the frontend to the backend or vice versa.
Enable CORS in Laravel: Laravel provides a simple way to enable CORS through middleware. First, install the laravel/cors package using Composer:

composer require laravel/cors

Next, register the package in the app/Providers/AppServiceProvider.php file:

use Laravel\Cors\CorsServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    protected $providers = [
        // ...
        CorsServiceProvider::class,
    ];
}

Finally, configure the CORS options in the config/cors.php file:

return [
    'allowed_origins' => ['*'],
    'allowed_methods' => ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
    'allowed_headers' => ['Content-Type', 'Authorization'],
    'exposed_headers' => [],
    'max_age' => 0,
    'cookies' => [],
];

Handle CORS errors: If you're making requests from the frontend to the backend and encountering CORS errors, you can handle them in Laravel by creating a custom exception handler. Create a new file app/Exceptions/HandleCorsException.php:

namespace App\Exceptions;

use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;
use Illuminate\Http\Response;
use Symfony\Component\HttpFoundation\Response as SymfonyResponse;

class HandleCorsException extends ExceptionHandler
{
    public function render($request, \Throwable $e)
    {
        if ($e instanceof \Symfony\Component\HttpKernel\Exception\AccessControlException) {
            return (new SymfonyResponse($e->getStatusCode(), $e->getMessage()))
                ->header('Access-Control-Allow-Origin', '*')
                ->header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS')
                ->header('Access-Control-Allow-Headers', 'Content-Type, Authorization')
                ->send();
        }

        return parent::render($request, $e);
    }
}

use App\Exceptions\HandleCorsException;

class AppServiceProvider extends ServiceProvider
{
    // ...

    protected $appMiddleware = [
        // ...
        App\Exceptions\HandleCorsException::class,
    ];
}

Make requests with CORS headers: When making requests from the frontend to the backend, ensure that you include the necessary CORS headers in the request. For example, when using JavaScript's fetch() function:

fetch('http://your-backend-url.com/api/endpoint', {
    method: 'GET',
    headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer your-token'
    },
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error(error));

Make sure that the backend also sends the appropriate CORS headers when responding to requests. This is already handled by the Laravel CORS middleware, but you can also set the headers manually in your controller methods if needed.