How to call web API?

1. First click on API Management in API Management tab then click the add new button for create new Api and fill details regrading the API. We also one entry bydefault you can also use this one.
2. After that Please click the SMTP & API tab, there we have some example and code that how you use the webapi in appliation/software/plugin. 
3. End of show response received after API call.

We have also make the video of this.watch to below video.