How to print from iOS device angular app to QLn420 printer through Bluetooth

General discussion
Audience
Public

I have an angular app host in iOS hand held device (e.g. iPhone). This app should print out the receipt to remote printer (e.g QLn420) by using Bluetooth connection between iOS device and printer. Is there any Lib or service can do this kind of printing? Thanks.

+--------+ +-----------+
| iOS | Bluetooth | Printer |
| +<----------------------------->+ |
+---------+ +-----------+