I want to retrieve data using API. How to do it?

[Div-shri]

Dear Team,

I want to retrieve the data or want to use PUT,GET, command for API which functionality is same of smartermail access.

How to do it?? What can be the 1st step to install it?? and how to use it?? Is their any proper documents step by step from installation till end.

[Div-shri]

I installed this API but it given the Json format answer but what if I want to disable the user or want to add the users using API?? How to perform the steps??