apt

 apt-get update --allow-releaseinfo-change

 

W: Failed to fetch https://deb.debian.org/debian/dists/buster-backports/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0E98404D386FA1D9 NO_PUBKEY 6ED0E7B82643E131

sudo gpg --keyserver pgp.mit.edu --recv-keys 0E98404D386FA1D9 6ED0E7B82643E131 0E98404D386FA1D9 6ED0E7B82643E131

gpg --armor --export DC30D7C23CBBABEE | sudo apt-key add -

sudo apt intsall debian-keyring debian-archive-keyring