Xubuntu 20.10
Version 1.17.73 Chromium: 87.0.4280.67 (Official Build) (64-bit)
I ran “sudo apt update” in a console window.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://brave-browser-apt-release.s3.brave.com stable InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY A8580BDC82D3DC6C
W: Failed to fetch https://brave-browser-apt-release.s3.brave.com/dists/stable/InRelease The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY A8580BDC82D3DC6C
W: Some index files failed to download. They have been ignored, or old ones used instead.