@Phelippe_Michel , I’m afraid it cannot work in n8n. The HTTP request you are trying to replicate is so-called Server-Sent Events (SSE) request. Browsers support this technology. Postman is built on Chromium engine. It is essentially a browser-based application. n8n on the other hand is built on a different technology, it is a node.js application.
Server-Sent Events (SSE) is a server push technology enabling a client to receive automatic updates from a server via an HTTP connection, and describes how servers can initiate data transmission towards clients once an initial client connection has been established. They are commonly used to send message updates or continuous data streams to a browser client and designed to enhance native, cross-browser streaming through a JavaScript API called EventSource, through which a client requests a particular URL in order to receive an event stream.
As your Postman screenshot demonstrates, a single initiation request resulted in a serious of responses from the server (Pi.ai API) - a few stream events pushed back to the client.
HTTP Request node only supports the standard HTTP methods.