I’m pretty sure the PM5 does not broadcast power on Ant+ as a power meter. In my digging around I found that folks had to use a bridge device of some sort to make a rower work on Zwift (or TR, but all of the references I saw were for Zwift).
Since you are on iOS you may be able to use this as a reference:
I honestly don’t know if it will work to run both the PainSled app and TR on the same iOS device or if it would require two.
Since I don’t have iOS I had to go the more hardcore route. You can see my recent thread on the subject. I’m doing it with a Concept2 SkiErg, but it should work with a rower just as well.
Maybe @Bryce can tell us if it would be possible to have TR implement the Concept2 Bluetooth power. I don’t know much about how the Bluetooth fitness devices work if there is a standard similar to Ant+ and if Concept2 implemented it or not. If they didn’t, I suspect TR won’t go through the trouble of adding it in for such a tiny group of us 