Auto Typer: Bluetooth Keyboard, will allow you to emulate a Bluetooth keyboard. The app is designed to save you time by saving scripts (strings of text) that can be automatically typed on demand.

Some examples of useful scripts to save typing time include: passwords, emails, urls and shell scripts.

The app operates by leveraging the Bluetooth HID feature available on devices running Android 9 or newer. This functionality enables the Android device to behave like a standard wireless keyboard connected through Bluetooth. As a result, it should be compatible with devices that supports Bluetooth keyboard connections, such as PCs, laptops, or phones.

Source code: https://github.com/tberghuis/AutoTyper