iCloud Recovery Key in 2020 ?

I'm trying to mess about with a early model iPod touch and in Settings>iCloud> I get told "User name or password is incorrect" and the choices to either Ignore or Edit.

Pressing Edit, the Account credentials pane opens, and I enter my current iCloud password, and then I'm asked for a Recovery Key.

I've googled about Recovery Keys and they all say to

1. Go to your Apple ID account page.
2. Sign in with your password and trusted device.
3. In the Security section, click Edit > Replace Lost Key.

Problem is, there's no option to "Replace Lost Key" on the Apple ID account security page (that I can see)

Is there another way to generate a new Recovery Key for pre 2FA iOS devices ?

tia