For normal operations, see Ground Control Station and Flight Controls section of the Flight Manual.
Many of the day to day operations are performed with the Vision Aerial Flight Deck mission planning and flight software and will not require users to need the user guides for the Herelink controller.
However, for advanced functions, the user guide for the Herelink ground control station is available on the CubePilot website at this location: https://docs.cubepilot.org/user-guides/herelink/herelink-user-guides