re:  “Select a MIDI port to send MIDI messages generated by Music Mouse.”

On my Windows 11 Pro x64 system, I don’t see anything in the list of destinations offered that will send the MIDI from the App to my DAW  (Fender Studio Pro 8.)  Most of the choices are MIDI outputs – not a destination for a signal:  KeyLab mkll 61, 2-UMC204HD 192k MIDI Out, LoopBE Internal MIDI, Sparrow 3×100, MIDIOUT2 (KeyLab mkll 61), Microsoft GS Wavetable Synth.

Also, why is there no choice for the Sample rate? My DAW, and all its plug-ins, are running 41000 Hz – that’s not a choice in your App.