Deleting iMac Login Password

Is it possible to remove / disable / turn off the login password on an iMac, like I can for the passcodes on my iPhone Pro and iPad? Why? Because I’m having trouble restoring a backup on a repaired iPhone. I’m definitely inputting the correct passcodes / password (I can successfully unlock all my devices using the correct passcodes / password). I was hoping to get around the “passcode verification” process without having to remove all my devices from my account …

It’s been suggested that the correct passcode for verification purposes isn't the current passcode used on the other devices but rather the very first passcode I used — when I first added each device to my account. That doesn’t seem right. See attached screenshot. And the User Manual / Support articles say nothing about having to use the initial passcode. If that suggestion is correct, then I’m stuck and will have to erase all the encrypted iCloud data associated with my account. That’s torture.

—— Scott