OpenGApps - FydeOS on Raspberry Pi400

I ran FydeOS on a Raspberry Pi400 today.

Has anyone installed openGapps on FydeOS (pi400)?
There is a downloadable opengapps in the Fydeos store. I have installed opengapps.
I try to start Google Play store and I get an error: the device is not certified (unable to add the account)

Plenty of tutorials out there, Google is your friend mate