I thought it is maybe the signature is not on antiX repository (not sure if that is how keys work, are they stored by participants who share P2P, not sure, new to linux and the intricacies of cryptography)
Err:4 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
…
Err:7 http://la.mxrepo.com/antix/buster buster InRelease
The following signatures were invalid: EXPKEYSIG DB36CDF3452F0C20 antiX (antix repo) [email protected]
Reading package lists… Done
W: 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
This part is what made me think the distro and brave “repositories” may not be aligned/updated?