GPG Error when adding repostory

[emailforos]

I followed the installation instructions in the README file and I get the following error:

GPG error: https://ppa.launchpadcontent.net/trzsz/ppa/ubuntu noble InRelease: The following signatures could not be verified because their public key is not available: NO_PUBKEY 7E51D1AD956055C

Anyone can help me to solve this issue?

Thank you.

Best regards

[lonnywong]

Try sudo apt update and sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 7E51D1AD956055C

[emailforos]

Thank you for your suggestion but I'm sorry but these commands didn't work:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 7E51D1AD956055C Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)). Executing: /tmp/apt-key-gpghome.9ylzn7QyVy/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-keys 7E51D1AD956055C gpg: "7E51D1AD956055C" is not a valid key identifier: skipped

Any other idea?