Open XR support with Web XR application

I am looking to build web based application using Threejs using webXR. I want to know how to integrate my application with Open XR to make it accessible for all device browser.

If you’re using WebXR, you’re at a level above OpenXR. Individual browsers may (and several do) implement WebXR using OpenXR, with no particular action needed on the part of the content developer that I’m aware of.