Well, the good news is that there are some guides out there.
The bad news is that iOS is going to be a bit trickier than Android.
Building an AR app for iOS is not any different from building any iOS app. Epic’s page in this is pretty good.
https://docs.unrealengine.com/5.2/en-US/setting-up-an-unreal-engine-project-for-ios/
I’d certainly start there.
There are some YouTube videos on the process as well:
YES, you are going to need a Mac to build for iOS. You can do a remote build from a Windows machine, but even then you need a Mac to “remote” into.
No, a virtual machine will not work, at least not in my experience.
There are some Cloud services out there that allow to “rent the machine”. also sometimes called “bare metal” What you need to make sure of is that you are getting an actual machine not a VM since a VM won’t work.
I found these folks, but I don’t know anything about them, There are most certainly others out there.
https://flow.swiss/mac-bare-metal
In my opinion, the better way is to go buy a used M1 Mac Mini off eBay. Looks like you can find one for less than $500 USD.
Whatever way you go you should assume that you’ll spend several days getting this up and working, especially since this is your first time building for iOS.
ALSO, there are currently bugs in both 5.2 and 5.3 that prevent AR from properly working right on iOS.
There is a fix for the 5.2 bug, but no fix for the 5.3 bug.
I hope this all helps.
-e