First Install Jwt composer Then
Set .env file JWT_SECRET = 'JWT SECRET KEY SAMPLE HERE'

Then Open Filters Implement app/Filters/AuthFilter.php app/Config/Filters.php Help website https://www.binaryboxtuts.com/php-tutorials/codeigniter-4-json-web-tokenjwt-authentication/

$routes->group("api", function ($routes) { $routes->post("register", "Register::index"); $routes->post("login", "Login::index"); $routes->get("users", "User::index", ['filter' => 'authFilter']); });