Issue with calendar add and update event

Issue with calendar add and update event

In Zoho calendar add and update event you mentioned that to send the data in the body if i am trying that one but i am getting the error like "event data missing". In try it example which you have mentioned bottom of the documentation you are sending the data in query string I tried in that format also but  i am getting the error like "bad request" ,Please could me help me out with how should i send the data to get the actual response.I have attached the screenshots i have tried please help me out with the response.
Thank you in advance.