The program gives you a blank save file to act as the holder for whatever mons you import/create. That OT is indicated at the top of the program.
As indicated by the popup, the handling trainer is expecting PKHeX, because that is the handling trainer. The original trainer is from Gen4, and you are editing in a Gen9 context (Violet), so the OT could never be handling it anyway. If you want to be in a different context, load your save file, or change the program settings to change which blank save file context is loaded.
Plugins not updated by the original plugin author may still be maintained by others who have made a fork.