error downloading the repository

[J-M-pixel]

git clone --recursive git@github.com:NVlabs/dex-ycb-toolkit.git

Cloning into 'dex-ycb-toolkit'...
Warning: Permanently added the RSA host key for IP address '140.82.121.4' to the list of known hosts.
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

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

Could you please help to resolve ?

[ychao-nvidia]

This seems like an SSH key issue. Have you tried adding your SSH key to your GitHub account?
https://docs.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh