Need to remove "test" iMac from iCloud and add "named" iMac to iCloud account

Mac OS 11.1 on my iMac. During a previous problem resolution effort I created an account named "test" fore the iMac. (Apple support had me do this.) Since then I have deleted that account from the iMac. Now, since 12/25/20, my iCloud reflects that "test" iMac in lieu of my actual iMac. I checked and the "test" account is not on the iMac.

I went on the Apple support page and tried selecting Apple ID from preferences and follow their instruction to remove the "test" iMac. No way can I find "remove device" in the menu. Tried highlighting the device and then a right-click no luck. Then tried a left-click with the same results.

Anyone know how to get this resolved?

Thank you,

Tim