go have a look in YT Tutorials for the video on how to do this! or follow this set by set tutorial!
1st get unity 2019 any one try to get 2019.3.5f (make sure to install android with it)
2nd make ur project and click on build settings --> Android --> switch platform
3rd go on package manger and install XR interaction toolkit
4th Go on project settings --> down to the bottom at XR --> install it DO NOT CLICK OCULUS WHEN ITS DONE LEAVE IT ALONE THIS WILL MESS IT UP!
5th Go to player in project settings --> click on android --> XR settings --> then Xr support --> the + icon add oculus (if does not work try it again it does that its normal!)
6th stay on player settings but go to other settings --> Graphics APIs remove Vulkan it causes errors
7th add ur XR rig go to the project Hierachy --> + icon --> XR --> Xr orgin (that will add vr support and ur own hand models follow valems tutorial to do that!)