iPad went missing but doesn’t show up on devices signed into Apple account or devices

When logging into Mac, i receive options to enter passcode for 2 iPads and a separate iPhone, none of which show up on my device list under my Apple account. How can i find out if these are accessing my account or how to remove them. Apple support was no help.

additionally, when trying to connect to iCloud on Mac, it specifically asked for passcode to ‘iPhone’ which is not the name of my iPhone attached, and the passcode I entered is incorrect, though I know it’s right.