yes, i did. now after fixing
sudo apt-key list
…
/etc/apt/trusted.gpg.d/mender.asc
---------------------------------
pub rsa3072 2020-11-13 [SC] [expires: 2024-10-23]
E6C8 5734 5575 F921 8396 5662 2407 2B80 A1B2 9B00
uid [ unknown] Mender Team <mender@northern.tech>
sub rsa3072 2020-11-13 [E] [expires: 2024-10-23]
the error changes
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://downloads.mender.io/repos/debian ubuntu/focal/stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 24072B80A1B29B00