I'm trying to launch preview of the game but it's always says "This page is not responding" How to fix this?
Viewing post in WebXR GDevelop Extension comments
How are you trying to launch preview? Since this is WebXR extension, it works only with web builds, and web builds must be loaded through a web server, you can't just double-click on the html file and load it in the browser.
Other than that the process is exactly the same as if you're publishing any web (html5) export of any other GDevelop game.