I am following the instruction
To install Stardog using apt-get run the following commands:
curl http://packages.stardog.com/stardog.gpg.pub | apt-key add echo "deb http://packages.stardog.com/deb/ stable main" >> /etc/apt/sources.list apt-get update apt-get install -y stardog[=<version>]
This will first add the Stardog gpg key to the systems and then fetch and install the latest Stardog deb package.
At step 3 'apt-get update' I get the following error
Err:7 http://packages.stardog.com/deb 3 Release 404 Not Found [IP: 18.104.22.168 80] Hit:8 http://archive.ubuntu.com/ubuntu focal-backports InRelease Get:9 http://packages.stardog.com/deb stable/main amd64 Packages [4461 B] Reading package lists... Done E: The repository 'http://packages.stardog.com/deb 3 Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.
Actually step 4 may complete. Will update post shortly