any tutorial about AR? I see this project PlayCanvas 3D HTML5 Game Engine requires a pattern. is there an AR that doesn’t use a pattern? like when we press on the screen will bring up the entity.
There are two AR methods readily available, either with WebXR (which is only supported on Android) or with 8th Wall which works on iOS and Android.
which can definitely work on iOS and Android better
too expensive for me 
Depending on your AR needs, you should be able to implement an older Pokemon GO style yourself as that’s just a video feed with rotational data on phone.
Currently I think the only non-8th wall solution working for ios and android is marker based.
(till iOs gets any webXR support)
If you need to generate a marker, this site is the easiest way:
https://jeromeetienne.github.io/AR.js/three.js/examples/marker-training/examples/generator.html
But don’t change the pattern ratio, as this is not changeable for the playcanvas integration (as far as I know)
Could be a possibility but requires someone to port it to PlayCanvas.