Unable to add single address without having the xpub

[sjkjs]

I have an old address which is simply just a single public key and its corresponding private key. I do not have the xpub used to generate it.

I want to add a watch-only wallet in Specter where I just give it the public key for one address and can then see the transactions for that address.

This doesn't seem to be possible as Specter requires you to enter an xpub.

Can the ability to add individual public/private keys be added?