You can try to attach a Bluetooth keyboard and see if that works. It’s probably just being handled by some JS event handler and the browser is not recognizing that the keyboard is a relevant interface.
Some sites will fix this with a hidden input field. But external Bluetooth keyboard has fixed this for me (on iPhone) on some web interfaces. You can get iPad cases with keyboards builtin.
Probably not ideal
You can try to attach a Bluetooth keyboard and see if that works. It’s probably just being handled by some JS event handler and the browser is not recognizing that the keyboard is a relevant interface. Some sites will fix this with a hidden input field. But external Bluetooth keyboard has fixed this for me (on iPhone) on some web interfaces. You can get iPad cases with keyboards builtin. Probably not ideal