https://withblue.ink/2020/05/17/how-and-why-to-sign-git-commits.html
If a key expires, you can update the expiration date as follows:
gpg --list-secret-keys to list the secret keys and look up the key ID, alternatively gpg --list-keysgpg --edit-key <key-id> to open the gpg consoleexpire in the gpg console and follow the prompts to update the expiration datesave and quitYou can type help in the console for other available commands.