The thing is that both rower and bikeerg use the PM5. I know they have adapted the device to the specific application, but it would surprise me if they had modified the connectivity. From the outside they are exactly the same PM5. I cannot test it because at the moment my rower is too far away from the PC, but a way to check would be to see if after turning on the connectivity on the PM5 you see the option “connect via bluetooth” vs. “or connect with ANT+.” If it’s there, after choosing ANT+ you should choose the ANT+Power profile (there are a few types that come up on the menu).
Another possibility is to search the Concept2 forum – I seem to recall having seen people who managed to connect the rower to Zwift, and were discussing the topic.