I think you can already create these on the CHORD page (see Introduction to the CHORD Page, The Chord Page: Entering Custom Chords and The Chord Page: Inversions under Tutorials topic, and the Scaler 2 Course Module 3 - Exploring the Chord Window),
ADDENDUM: Another option would be to play the chords in and record them using the detect function. This works very well with block chords from a midi device, but the chord may not be given the name that you expect as Scaler assigns names based on its interpretation of the scale.