@erohmensing, frankly the API is not completely thought out well in my opinion. Certainly not from the perspective of someone trying to migrate from Rasa to Rasa X.
Please note issue #4185 - the PUT /templates call supports only a json format. It does not support the domain.yml format that is used for Rasa bots.
The Rasa X UI should also have an import for templates in yml format.
I’m sure this will all be addressed in time and I appreciate the quick release schedule from the Rasa X team but after upgrading to 0.20.2 I’m stuck. Will probably go back a release for now…