It is really important to test the RESTful API completely. However, since RESTful API uses many elements which cannot readily be passed from browser, hence we shall use browser plugin such as Postman for chrome to test API You can install Postman for free from chrome store. Once you have installed it, you can start the API testing Fun.
Next thing you need to select for the API call is, set the API endpoint and select the HTTP verb from the Postman interface.
Since for many APIs you will need to pass Auth basic content to access pages that need authorization, see below image to pass the data.
For some of the APIs (POST / PUT) etc, you will need to pass the JSON data. See below image to pass the data correctly
Remember to select Content Type header, since without that the JSON data will not be parsed and API may not work