If your wok has a flat bottom, then it’s not a wok. The circular shape of a wok diffuses heat up the sides, which a flat bottom pan doesn’t do. A flat bottom pan also doesn’t allow you to toss whatever it is you’re frying properly. If an induction cooktop was capable of providing the appropriate amount of heat, this would simple end up burning some of the food. However, it most certainly is not. An induction cooktop _might_ be capable of heating a pan up to the appropriate temperature (I’m skeptical about that), but it can’t keep it there. That temperature will drop the moment you put anything in it, and if you want to properly stir fry something, you need your wok to keep that scalding temperature the whole time you’re cooking.

You can cook food in a flat bottom frying pan on an induction cooktop, but you can’t do anything close to a traditional stir fry technique.