How to return unauthorized using Laravel API Authentication

Please add the method in the class Handler in the file location app/Exceptions/Handler.php

/**
 * Convert an authentication exception into an unauthenticated response.
 *
 * @param  \Illuminate\Http\Request  $request
 * @param  \Illuminate\Auth\AuthenticationException  $exception
 * @return \Illuminate\Http\Response
 */
protected function unauthenticated($request, AuthenticationException $exception)
{
    if ($request->expectsJson()) {
        return response()->json(['error' => 'Unauthenticated.'], 401);
    }

    return redirect()->guest(route('login'));
}

And also add the following line above the class in the same file as mentioned above: use Illuminate\Auth\AuthenticationException;

In the postman within the headers section please add the following header : X-Requested-With:XMLHttpRequest

Hope this helps and resolves the issue. Thanks.

Be sure to be sending the right headers in your request

Content-Type: application/json