No valid OpenPGP data

hello, my system:
Distributor ID: Ubuntu
Description: Ubuntu 20.10
Release: 20.10
Codename: groovy

Linux homeserver 5.8.0-63-generic #71-Ubuntu SMP Tue Jul 13 15:59:12 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

my first command is,
wget -q “” -O- | apt-key add -

the output is:
apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
gpg: no valid OpenPGP data found.

unfortunately I have no idea what to do there
can someone help me?

many thanks

First time I see this, I guess it’s new. I wonder what is the new standard now.

Anyway it does not explain why it does not work for you, since apt-key is supposed to keep working, it’s just not recommended anymore.

Could you try just wget to make sure you can actually download that file? Maybe the download fail for some reason in your case (like a proxy that prevent it) and it try to add as GPG an error message.