Finding Problem in Check out from Git

As per setup procedure given
I am trying to use -
$ git clone

But facing problem as per following message -

Cloning into ‘circt’… Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Please allow me to download code for CIRCT.
Manoj Bansal

Is it possible that you don’t have a SSH key generated on this machine/account? (To generate one, use ssh-keygen)

To debug SSH connection to GitHub you may try ssh -vT