Install Docker on Debian testing

Install prerequisites:

sudo apt-get install apt-transport-https ca-certificates curl gnupg-agent software-properties-common

Install GPG key and repository:

curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -

To avoid error on apt update:

E: The repository 'https://download.docker.com/linux/debian sid 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.

add docker buster repository:

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian \
buster \
stable"

Install Docker:

sudo apt-get update
apt-get install docker-ce docker-ce-cli containerd.io