Knot is currently unsigned. After you've installed it in /Applications, macOS will refuse to launch it, and Gatekeeper's TCC checks will block it from making network connections, until you remove the quarantine flag and ad-hoc sign it:
xattr -d com.apple.quarantine "/Applications/Knot.app" codesign --force --deep --sign - "/Applications/Knot.app"
Run both commands in Terminal, then launch Knot normally.
Something not covered here? Let us know, or open an issue on GitHub.