Authentication SSH key for git?

Hi,
as you know you can add signingkey to .gitignore and that you can ha different siningkey depending on computer, repo etc.
But what I'm also wondering if it's possible to have the same for authenticationkey somehow?

Github has the option to upload the authentication ssh certficitation so it should be possible but I can't find anything when I'm googling.

1Password Version: 8.10.0
Extension Version: Not Provided
OS Version: macOS 13.2
Browser:_ Safari