@MrT10001 Thanks. I looked through the forums and don't see it the model listed as a port subtopic, only a number of threads which talk about attempts to install with varying success.
It looks like I would need to downgrade from Android 10 to Android 9, then install Ubuntu.
However, given there are some posts saying the downgrade bricked the device, and lots saying that it didn't work properly, and some saying that the port is now dead, it doesn't seem like something that's a good idea for me to try, so I will unfortunately need to stick with Android.
Seems like I'm not the only one to have bought a device matching the "2nd Gen" description then discovered it's not the right model number. A shame.