Problem with rear brake of Xiaomi 4 gen 2 pro

I bought this scooter. How do I know if the rear brake works or not? I have the impression that only the front brake works but I don't know how to check. I read on the Xiaomi website that the rear brake works via E-abs (and not via a drum like the front one), but I don't know how to test it. When stationary I know that it doesn't work for sure because the rear wheel continues to move even though the brake lever is pressed.