Receiving empty body from fiware post request

Hi, I am trying to use a custom node to recive a post request from fiware orion but the body of the request is empty.

This is the code i use for the request:

This is what i receive:
Captura45

I have tried to use the http in nodes to recive the same request and they show the body without problems.

I dont know what i am doing wrong, i would appreciate some help.