Smartphone-to-USB Communication: Android Interface

I'm in need of a seasoned developer who can create a simple application in Android Studio, preferably in Kotlin or Java, with a straightforward GUI consisting of just two buttons:

Button1 = "ON"
Button2 = "OFF"
The application should use a USB OTG cable to connect an Android tablet with version 11 to any Arduino device. When the user presses Button1, the application should send the string "ON" through the USB serial port, and if Button2 is pressed, it should send the string "OFF" via USB. I'm interested in one-way communication only, and the application should be as simple as possible.