That would be a problem. For Scaler to recognize chord in audio or midi there has to be chords there already.
A melody can be sung to multiple chords. What you can do is make a guess and play/sing along with Scaler as you try different chords and jot them down.
If you had your voice with two harmonies recorded and fed that into Scaler that might work for you. As long as there are chords to recognize Scaler will do that for you.