Installing MS SQL Server on Debian 11 -- Repo Signature Problem

trying install MS SQL Server 2022 on Debian 11 is driving me crazy, as I'm not being able to add MS repo properly. First of all, step-by-step guide by Microsoft -just for Ubuntu- in this page: https://learn.microsoft.com/en-us/sql/linux/quickstart-install-connect-ubuntu?view=sql-server-linux-ver16&preserve-view=true I add the the repo and import the public key, but doing sudo apt-get update gives the following error:

Error: https://packages.microsoft.com/ubuntu/20.04/mssql-server-2022  focal InRelease: the following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF

I try importing again, but this time using gpg, importing the public key:

--recv-keys --keyserver https://packages.microsoft.com/keys/microsoft.asc  EB3E94ADBE1229CF

The key was added, I even check it with Kleopatra an the public key is imported. But then again, doing sudo apt-get update, I get the same error again!

Error: https://packages.microsoft.com/ubuntu/20.04/mssql-server-2022  focal InRelease: the following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF

I don't understand why apt-get cannot find the public key, if it is correctly imported. Thanks in advance!