I was trying to install docker. I tried sudo apt-get install docker-ce docker-ce-cli containerd.io but there is no installation candidate available. I don't remember exactly what I did next (maybe just apt install docker-ce?) but the terminal recommended: sudo apt install docker.io I did that and docker is now running properly but now when I run apt update I get the following errors: E: The repository 'https://download.docker.com/linux/ubuntu odin 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. docker works but a. how do I get rid of this message every time I run apt update b. how should I update to newer versions in the future?