How to get header variable from response call api?

I am creating a project where I have a first-call API to authenticate. This call responds a header with a variable called "set-cookie". I need to get this value and pass into the others calls in the header.

In Flutter, I used this way:

Map<String, String> header = response.headers;
setCookie = header["set-cookie"]!;

But in FlutterFlow, when I try to get this same field using the "get response header", I get an empty array:

Inside the debug panel, there isn´t a "header" variable.

The same call, using Insomnia, I have a lot of information inside the header:

How to get access at this information?