You best option to enable a web application on a Zebra Android device is to use Zebra's Enterprise Browser and it's PrinterZebra API.
Another option could be to use Android Intents from Chrome from Android or in the standard browser in the latest Android version:
You can then send Intents from your web page to PrintConnect: https://developer.zebra.com/community/click2demo/blog/2015/09/28/printconnect-by-zebra-technologies
A last option could be to use WebBluetooth API: https://caniuse.com/#feat=web-bluetooth
In this case you will need to verify that you can have the latest version of Chrome for Android (v64) to support this proposed standard and then implement all the low level communication with the printer.