Can anyone help me with these errors? Thanks in advance
Code
Err:7 https://download.mono-project.com/repo/ubuntu stable-bionic InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A6A19B38D3D831EF
W: GPG error: https://download.mono-project.com/repo/ubuntu stable-bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A6A19B38D3D831EF
E: The repository 'https://download.mono-project.com/repo/ubuntu stable-bionic InRelease' is not signed.
Search the files under /etc/apt/sources.list.d/ and remove that REPO wherever it's mentioned.
After run and post the output of:
omv-update (or omv-upgrade, never remember which one is it)