How can I create an level where when user has tapped the screen, it puts them into the level using the HandHeld Mobile AR Template?

So I am new to developing games, I am trying to make a mobile AR game where when the user has tapped the screen or a button, it matches a custom made level where it shows only a virtual world which is ontop of a surface. It is as if it is a pair of glasses, the button (when pressed) strips your vision of reality and puts you into a new world.

This will made for IOS if I can find out a way to put it onto my iPhone X without going through the app store, or just getting an android phone.

Can anyone tell me how I can achieve this?

I am having the same issue in the handheld AR blueprint. See video below, which shows how to perform it manually in version 4.17.