Maybe the posters in this thread have not accounted for the main issue, which is connecting to an iPad Pro.
If we’re talking about a 2018 iPad Pro, it doesn’t have a Lightning connection, but an USB-C. So, what might work is to take a standard USB Ant+ dongle and connect it to the iPad Pro via a USB-C adapter. No more need for the 30pin dongle and 30pin to Lightning adapters. I haven’t tried it, but it may be worth a shot.