This is a little mod to enable Bluetooth HID profile on Android devices that have at least android 9
Before installing this i recommend to check your device compatibility here https://play.google.com/store/apps/details?id=com.rdapps.bluetoothhidtester&hl=en ,because you don't need to use this if your device has already it enabled,also this its under testing,so idk if this works for your device,so dont blame me if something goes wrong (even if this should be secure),its advised to do a backup of your system bluetooth apk.
OnePlus user could have some problems enabling HID support,some suggested to change their ROM to lineageOS
Big thanks to ysc3839 for the enabler apk https://github.com/ysc3839/magisk-bluetoothhidenabler, you can use his module for older magisk versions(21.4<)
EDIT: Tested and working on Android 10 with magisk 23.0,if something isn't working try to see issue section