Bitcoin & Python Code

Some websites have a sign-in feature where you digitally sign a message with your node & they automatically know who you are. (Amboss for example)

Does anyone have any sample code or github links to code that does the signing & verification?

Some wallets have this same feature, which appears to use one address. I presume this is different from the node-based signing. Any code available to do this address-based signing?

I’m writing something in python & could use a pointer or two.