All methods defined in the WSDL schema for the vSphere Web Services API can be invoked by using a REST-like URL with the POST verb. The method name appends to the URL and the method parameters appear as JSON in the body of the request.

Method names begin with an uppercase letter and match the method name in the vSphere Web Services API Reference. All methods attach to a managed object reference, as in the SOAP API.

For example, the SessionManager managed object has a method whose WSDL name is AcquireLocalTicket.

The URL format that you use to invoke a method is 
https://vcenter_fqdn/sdk/vim25/8.0.1.0/mo_ref/method_name

For example, you invoke the AcquireLocalTicket method with a URL like this:

https://vcenter_fqdn/sdk/vim25/8.0.1.0/SessionManager/SessionManager/AcquireLocalTicket
When you POST a request to invoke a method on a managed object, the body of the request contains a single anonymous JSON object that specifies the parameter names and values. Unlike the SOAP request protocol, the JSON does not specify a reference to "this" because the managed object reference is in the URL path.
For example, the method Folder.CreateFolder requires a name for the new folder. The body for that request would look similar to this: 
{"name": "spare_VM_folder"}