Files to download are at the very bottom in the "Assets" block.
You need either dfint-installer-win-*.zip file (for Windows) or dfint-installer-lin-*.tar.gz (for Linux).
NOTE: Antivirus software may give false alarms. The installer simply receives data and files from the Internet and adds or replaces files in the game folder. Antivirus programs may interpret this as potentially malicious behavior, but it is just how the installer works.