One of the strong features of Visual Builder Cloud Service is the ability to consume any REST service very easily. I have a video that shows you how to work with REST services in a completely declarative way, but that video doesn't show you what happens behind the scenes when you work with the quick starts. In addition, that video shows using the GET methods and several threads on our community's discussion forum asked for help working with other operations of REST.
The demo video aims to give you a better insight into working with REST operations showing how to:
A couple of notes:
In the video I use the free REST testing platform at https://jsonplaceholder.typicode.com
While I do everything here manually - you should be able to use the quick starts for creating a "create" form and map them to the post operation - as long as you marked the specific entry as a "create" entry like I did in the demo.
If the concepts above such as types, variables, action chains are new to you - I would highly recommend watching this video on the VBCS Architecture and Building Blocks, it will help you better understand what VBCS is all about.