Example how to send a message to the WebChat widget

I'm writing python script to receive webhook new-message notifications and reply with some text. I setup a webhook but I still cannot write a Python code to send the reply.

There are some many docs related to Chat API / Conversation API / GraphQL API / Sunshine API and I still dont understand which one I should use.

Also I lost in 5 different types of authentication.

What type of authentication should I use with a data from 

https://{subdomain}.zendesk.com/admin/apps-integrations/apis/conversations-api

I know my

SUBOMAIN

APP_ID
KEY_ID
SECRET_KEY

 

For the "send-message" API I a bit lost in too many docs and still cannot figure out how to solve such a basic problem.

I still cannot find any clear instruction or manual what exactly should I do to send "hi" to web-chat-widget

 

I have a data from "new-message" webhook and I see conversation_id inside

 

Can you give me example of curl / python code I should execute to send a reply message with the following

 

- HTTP method

- domain

- API path

- headers

- requests data

 

Thank you very much