Hi,
whenver I am running apt update I am seeing thsi error:
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://apt.radxa.com/bionic bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B99C4BEFEC47E96E
W: Failed to fetch http://apt.radxa.com/bionic/dists/bionic/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B99C4BEFEC47E96E
W: Some index files failed to download. They have been ignored, or old ones used instead.
Does anyone know how this can be fixed ?