Question about ASUS ZenScreen MB16AC

Since the screen is powered exclusively via the USB-C port, I don't think that will work (for long). Powering a 15-inch monitor with a mobile phone battery is likely to overload the phone's battery.

...as far as I know, it doesn't work with iPhone products because they still have the Lightning connector. It works with Android.

It comes with a USB-C cable. Simply connect it to the iPad.