Swagger and Powershell safeguard-ps module

Hello everyone, 

as you know is it possible to perform an Identity Provider synchronization via Powershell? I only was able to do it via Swagger and even copypasting Swagger code in Powershell or using the request url seen on swagger, it doesn't work and an error (Remote server error: (415) uNsupported media type) is shown.

Thank you!