Unable to change primary email for Apple Account

I only have a Mac computer running 14.1.2, I'm trying to follow the instructions here Change your Apple Account primary email address - Apple Support, I enter the new email I want, and am then presented with this modal.

The thing is, on the one part I can only see "Apple ID" in System Settings, I don't know where "Apple account" is located, on the other part I tried looking into every option inside "Apple ID" just in case but couldn't find anything. Anyone know what I have to do?

[Re-Titled by Moderator]