Problem installing on Debian on apt-get update
When installing Nuxeo LTS 2016, I have a problem installing it on a Debian server. I used the official documentation protocol from “From the terminal”: https://doc.nuxeo.com/nxdoc/installing-the-nuxeo-platform-on-linux/
So I used the lines with “releases”. Now I have a problem with this line: apt-get update. (I'm already in root so no need to use sudo). All the other lines run smoothly to that one and the installation of Nuxeo the next line does not work so this line is really embarrassing.
The problem is : The following signatures could not be verified because the public key is not available (See screenshot (I translated the French sentence previously)).
You will find enclosed a list of the commands used.
Thank you very much for your help