Looks like its just expects a HTTP post. I would just use a HTTP connector instead of using the sharepoint module. Not sure what is happening under the hood for the sharepoint connector.
Few things come to my mind Roland 1: Check if you can perform the action of adding lists from a http client outside of workato. 2: If getting the list of sites and adding a new site (I am assuming you are trying to create a new site when you say addi...