Axon don't allow it in android 9 because it doesn't activate. I use tincore keymapper which has more functionality than all other keymappers, it can also make your phone a gamepad for Bliss os or Android x86, it also doesn't require external mouse/keyboard. It even allow mapping different areas of touchpad to different functions. In short only people who know the potential of tincore keymapper, use it. One of the most useful apps on the play store, make sure you have signed into the beta and have version 3.7.8 beta version. Gamehelper and panda mouse are for noobs.