orthanc-cli provides pre-build completion files for Bash, fish and Zsh. The completion files are located in completion directory. This directory is also bundled with each release tarball of orthanc-cli.
First make sure bash-completion package is installed on your system. Refer to the official
documentation for installation details. Then put the file
orthanc.bash into ~/.local/share/bash-completion/completions/ directory.
Put the file orthanc.fish into ~/.config/fish/completions directory.
Put the file _orthanc into a directory of your liking (e.g. ~/.zsh_completions), and add this directory to your
fpath: fpath = ($fpath ~/.zsh_completions).