W: GPG error: https://brave-browser-apt-release.s3.brave.com focal InRelease: The following signatures were invalid: EXPKEYSIG 4FE13824E3FFC656 Brave Software <support@brave.com>
E: The repository 'https://brave-browser-apt-release.s3.brave.com focal 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 user configuration details.
E: https://brave-browser-apt-release.s3.brave.com focal InRelease is not (yet) available (The following signatures were invalid: EXPKEYSIG 4FE13824E3FFC656 Brave Software <support@brave.com>)