I try to access IBM conversation using Postman tool but getting 404 (Resource not found) error.
EndPoint : https://gateway.watsonplatform.net/conversation/api/v1/workspa
Your endpoint looks correct if you're trying to send a message to conversation: https://www.ibm.com/watson/developercloud/conversation/api/v1/?curl#send_message
Try changing the version to the most updated: version=2017-05-26
version=2017-05-26