This is not a "plug-and-play" black box software like some dedicated ductulators (e.g., Elite CHVAC). It requires a solid understanding of Excel. You are essentially building your own calculator using their engine. If you aren't comfortable with Excel formulas or VBA, the learning curve is steep.
The search for an is a rite of passage for HVAC engineers. The smart ones stop searching for a magic download link and instead learn to import the licensed Access database into Excel using Power Query.
Instead of manually reading complex logarithmic charts (like Chart 14-3 or 14-4 from the 1997 Handbook), the digital database allows engineers to compute dynamic losses instantly using standardized formulas: ( \Delta p = C_o \times P_v ) (where ( P_v ) is velocity pressure).
If you are still calculating duct losses by hand or using a plastic slide rule, you are working too slowly. The Excel link allows you to build robust, auditable, and repeatable calculation sheets that can be saved for future projects.