The latest version. Needs an Immich v3 server.
Or with Homebrew, then the same step 2:
brew tap brofrong/tap
brew trust --cask brofrong/tap/sd-sync-immich
brew install --cask sd-sync-immich
chmod +x SD-Sync-Immich-x86_64.AppImageOr the Flatpak instead of the AppImage. It does not update itself: install each new version the same way.
flatpak install --user SD-Sync-Immich-x86_64.flatpak
Checksums, command-line binaries and older versions are on the GitHub releases page. Full instructions are in the README.