I get some error with sudo apt update,about git pub key

Question

fazil@acer:~$ sudo apt update W: GPG error: https://cli.github.com/packages stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C99B11DEB97541F0 E: The repository 'https://cli.github.com/packages stable InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.