First of all as per the requirement you have to decide which http method(Get,Post,PUT) you are going to use.
Then Create connect Rest rule and select HTTP method and HTTP version under service tab.And Enter your endpoint url.Note: This URL can change over time, or can change when you move between a test system and a production system. However, after the RuleSet version containing this connector rule is locked, you cannot update this field. If your application needs to override the value in this field, complete the EndPointURL parameter of theConnect-REST method in the connector activity that calls this connector rule.
2. In Request tab give ur header fields like content-type/encoding/Content-Encoding. And in message data you have to give mapping detals like where you have to map from.(Clipboard/Constant etc.)
3.In response tab again you have to fill message data form with response keys.
For testing you can use Connect-REST method to call created connect rest rule and check its is working.
Connect Rest Connector is as simple as SOAP connector and very close to HTTP connector implementation. It supports 4 method - Get(Read) /Post(Update) /Put(Insert) /Delete(Delete).
The Resourse path holds the end-point urls and in case the endpoint url holds param in path same is supported with resourse param. The query string param on method tab is for passing param which comes after "?" in incomming request.