@Mahesh, sorry for the confusion. iOS doesn’t allow websites to go full screen as a result of a user action (iOS doesn’t support the fulscreen API).
What you can do is to add a home screen shortcut for the scene, as described in https://www.makeuseof.com/tag/add-website-shortcuts-iphone-home-screen/, and then open the scene through the shortcut. It will be then run in the full screen mode.