How to Reset MacBook with old email address used for apple account.

This address is inactive and I've already signed out with the newer email address for this account. I'm being asked to enter the password for this old email in order to turn off Find My even though it's already done for the new email on the same account. I tried to reset the password for the old email but the apple support app says the apple account is either not valid or not supported.

Clearly changing the email on an apple account is not thought through properly by apple.