How can I sign a bitcoin address that is on a paper wallet? I have a bitcoin address that shows I held the BTC prior to December 2019.  I need to verify this but as the address refers to a paper wallet I don't seem to be able to do so.   If I move the coin to a hardware/software wallet I can verify BUT I will have created a new address that doesn't meet the criteria in that case.
Is there a way to sign a message with my paper based bitcoin address?  Or import the paper wallet into something that can sign messages?
Import private key of bitcoin address (paper wallet) in Electrum