How to update b1300 to latest openwrt keeping the gl ui?

I recently updated b1300 firmware v3.105 and still stuck on openwrt 15 (chaos calmer) which is ancient version.
I’m looking to build firmware image based on openwrt version 19.x but keeping the Gl UI.
Can anyone please point me to the right direction how should I do it?
I looked at GitHub - gl-inet/openwrt: This repository is fork from openwrt official repo, we will update the latest tag and release GL.iNet firmware based on it. but not sure if I build using this branch would it make build with gl ui or it’s just openwrt fork for sysupgrade?

Any help is appreciated.

No you cannot do it.