I am trying to create an android app to allow smartphone to act as a hid keyboard in kotlin

I am trying to develop an app which will make your smartphone act as a "keyboard". I need it to send different symbols to another devices via usb, acting like an hid keyboard. I am trying to make it work without rooting the phone. I'm using kotlin and java to do this. Does anyone have information on this topic? I tried looking for answers on this repo: https://github.com/Arian04/android-hid-client?tab=readme-ov-file But it seems that the author uses rooting and i don't think that it's a way for me. Also i need it to connect to devices via usb without manual settings. Also i seen this thread: https://stackoverflow.com/questions/3760600/can-android-emulate-a-hid-device But they are talking about bluetooth connection and nothing about usb. I just don't know how to approach it and wonder if anybody has some fresh ideas.