Issues on calling on-prem POST API

Hi all, 

I'm quite new in using Power Bi Desktop and my goal is to call internal on prem REST POST API from Power Bi Desktop.  If I use the classical possibility from WEB, I retrieve the error in the message. My workaround is to call it by using a curl command in the same machine on a bat file that is called by Power Bi Desktop by means of an R-script. In your opinion, is there a less messy method to achieve the goal?

Many thanks,

G.