I'm trying to install nala and I am getting this error:
W: GPG error: https://deb.volian.org/volian scar InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A87015F3DA22D980
E: The repository 'https://deb.volian.org/volian scar 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.
I am using Ubuntu 22.04



