From where does we get the sessionId ?

API and Webhooks
1 
GET https://api.zoom.us/v2/im/chat/sessions/{sessionId}
2

Hi Ammulekshmi,

To get the session ID you will need to use this API - https://zoom.github.io/api/#retrieve-im-chat-sessions. Afterwards you can use the session ID here https://api.zoom.us/v2/im/chat/sessions/{sessionId}

Thanks