ZQ520 Android Bluetooth pairing using predefined PIN

We're using RW420 printer to print receipt from an Android app.

We've configured a predefined Bluetooth PIN in printer and same we're passing from our Android app to pair and print automatically.


Now with ZQ520 printer every time it need to pair user need to press Accept button on printer to print.


How can I make ZQ520 printer to pair automatically through our Android app.