root@debian:/home/name# apt update
Hit:1 http://security.debian.org/debian-security stretch/updates InRelease
Hit:2 https://deb.torproject.org/torproject.org stretch InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
root@debian:/home/name# apt install tor deb.torproject.org-keyring
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package deb.torproject.org-keyring
E: Couldn't find any package by glob 'deb.torproject.org-keyring'
E: Couldn't find any package by regex 'deb.torproject.org-keyring'
root@debian:/home/name#