[git] Switch between user identities in one Git on one computer

I have ONE repository on GitHub, let's call it Repo-1.

I want to first access that repository as a default Git user.

Let's call that user User-1.

I created SSH keypair, everything fine, works nice.

I made ANOTHER repository on GitHub, let's call it Repo-2.

I didn't make any changes in local Git, on my laptop. No configurational changes, nothing.

Now - I want to clone from Repo-1 as the User-2 (but from the same laptop).

First of all: is this at all possible to do?

Can local Git on one single laptop switch between "user accounts" and present itself as User-2? And then, from THAT identity, clone from Repo-1, make some change, and then push to Repo-1?

If possible, how do I do that?