Docker packages for stretch release failing to be found on sudo apt-get update

Question

I've added the repository as per the tutorial https://docs.docker.com/install/linux/docker-ce/ubuntu/#install-using-the-repository

but when I run sudo apt-get update I get the following stack

Ign:9 https://download.docker.com/linux/ubuntu stretch/stable amd64 Packages
Ign:10 https://download.docker.com/linux/ubuntu stretch/stable all Packages
Ign:12 https://download.docker.com/linux/ubuntu stretch/stable Translation-en
Ign:13 https://download.docker.com/linux/ubuntu stretch/stable Translation-en_US
Err:9 https://download.docker.com/linux/ubuntu stretch/stable amd64 Packages
  404  Not Found
Ign:10 https://download.docker.com/linux/ubuntu stretch/stable all Packages
Ign:12 https://download.docker.com/linux/ubuntu stretch/stable Translation-en
Ign:13 https://download.docker.com/linux/ubuntu stretch/stable Translation-en_US
Reading package lists... Done
W: The repository 'https://download.docker.com/linux/ubuntu stretch Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch https://download.docker.com/linux/ubuntu/dists/stretch/stable/binary-amd64/Packages  404  Not Found`

My /etc/apt/sources.list is as follow

deb http://deb.debian.org/debian stretch main
deb http://security.debian.org/debian-security stretch/updates main
deb [arch=amd64] https://download.docker.com/linux/ubuntu stretch stable
# deb-src [arch=amd64] https://download.docker.com/linux/ubuntu stretch stable

Answer 1

Ubuntu doesn't have stretch. You probably clicked on the wrong link on the docs. Replace ubuntu in the sources.list file URL with debian, as you seem to be on a debian machine.