Help with getting latest MuseScore to work with Kontakt 6 Player on MacOS 10.15

I have a Kontakt Player sound library (Audio Imperia's Nucleus) and I would love to be able to connect that to the latest version of MuseScore. I have tried using the JACK audio method but JACK is no longer supported on MacOS 10.15+. This video showcasing an early version of MuseScore 3 seems to accomplish exactly what I want to be able to do: https://youtu.be/esNlwwcwOjo?t=235
This video uses a Soundbanks feature which I believe has been deprecated and I also do not know where I would find the .xml file used to load in the sample as shown in the video.
The library uses .nki files for all the instruments so if someone knows how to get those to work with MuseScore that would also be an option.
If anyone could help me it would be greatly appreciated!