Zoho desk webhook

I want to setup zoho desk webhook through API, i have already initialized my endpoint, but each time i make the call i get the following error : Raw response for the API Status code 422 {“errorCode”:“UNPROCESSABLE_ENTITY”,“message”:"Validation failed for the condition : The endpoint failed to respond with status code 200 "}

If i change the backend endpoint to GET, the call goes through.

How will i be able to fix this, i already tried the return data Api it still didnt work.

Thanks