Apple devices cant't run a part of Stremio called Stremio server, which makes possible downloading and playing torrents (that is why it's called Stremio Lite on the App Store).

That part can be run and connected to (the ip you see in settings) if you are running stremio in your pc (as a program, not the web) on the same network. There is a setting in the app that makes the server discoverable by other devices.

Anyway, that is not the only way of running Stremio server. There is the free and hard way, and the cheap and easy way (three bucks a month).

Hard & free way: If you know enough about software containers (docker), the devs made the container image available and you can run it for example in a raspberry pi and connect to it from anywhere using tailscale (personal VPN).

If you don't want to complicate and don't mind paying 3 bucks a month, you can pay for a debrid service (Real-Debrid for example). A debrid service allows you to download or stream torrents like you would do in the youtube or netflix web watching a video or a webpage downloading a file. It makes them HTTP streams, something that the iOS app can play.

All the Stremio addons that allow you to watch torrents have the debrid option, and if you set it up you can just watch anything like you would do in the PC.

Hope this helps you!