simple API and how to use it

You can define your api in routes/api.php and write the first api:

Route::get('foo', function () {
    return 'Hello World';
});

and run it: http://{your_host_url}/api/foo

Check it for more info: https://laravel.com/docs/7.x/routing

you can go to routes folder then u will see api.php

Route::get('foo', function () { $users = \DB::table('users')->get(); return response(['message'=> $users]); });

whenever we work with API we don't have any interface if you want to test it you have to use Postman https://www.postman.com/

@jeloumc Read the docs. Everything you need to know is in there.