Either:

a) download pre-converted models from here https://drive.google.com/drive/folders/1wFy1Y0pqoK23ZeMWWCp8evxWOJQVdaGh 

or

b) follow the guide on quantizing other models here https://github.com/ravenscroftj/turbopilot/wiki/Converting-and-Quantizing-The-Models