How to add Connector in developer platform zoho?

How to add Connector in developer platform zoho?

Hi, I am working on creating an Extension, and part of the development is to retrieve Email templates.
In my CRM instance I can invokeURL by creating Zoho OAuth connection and get the template.

But developer platform does not provide Zoho OAuth or any other connection by default. How can I fetch templates? I dont know where to get CRM connection fields which are below. Please help on this.