Any documentation on 'Call HTTP Web service' POST operation??

I have tried using the Call HTTP Web Service actions POST operation to create a folder in the document library of Office 365 site. To do any kind of POST operation with REST services, We need to pass in some headers like  "Authorization","X-RequestDigest", "content-length".

 Is there any way to get this information in our Nintex workflows?

Thanks,

Shaun