I have a problem installing Wine after installing the latest upgrade.
The following signatures couldn't be verified because the public key is not available:
NO_PUBKEY 76F1A20FF987672F
Reading package lists... Done
The repository is not updated and the previous index files will be used.
W: GPG error: https://dl.winehq.org/wine-builds/ubuntu bionic InRelease:
The following signatures couldn't be verified because the public key is not available:
NO_PUBKEY 76F1A20FF987672F
E: The repository 'https://dl.winehq.org/wine-builds/ubuntu/dists/bionic InRelease' is not signed.
W: Updating from such a repository can't be done securely, and is therefore
disabled by default.
W: See apt-secure(8) manpage for repository creation and other user configuration details.