Transfer-encoding chunked in golang proxy

Question

I'm new to golang and I'm trying to build a small local proxy. The request kinda works from Postman -> localhost:9097 -> localhost:9098 and back. But the content-length is 120 and the response body is just gibberish:
I expect to get a json body like { "result": { "id": "1", "price": 100, "quantity": 1 } }

If a make a request directly to :9098 I see that the response header transfer-encoding is chunked. Any idea how to adjust my code to parse the response body from the server properly and send it back to the client?

func httpHandler(w http.ResponseWriter, req *http.Request) {
    reqURL := fmt.Sprint(req.URL)
    newUrl = "http://localhost:9098" + reqURL

    //forward request
    client := http.Client{}
    freq, reqerror := http.NewRequest(req.Method, newUrl, nil)
    if reqerror != nil {
        log.Fatalln(reqerror)
    }
    freq.Header = req.Header
    freq.Body = req.Body

    resp, resperr := client.Do(freq)
    if resperr != nil {
        log.Println(resperr)
        fmt.Fprintf(w, "Error. No response")
        return
    }

    defer resp.Body.Close()

    body, ioerr := io.ReadAll(resp.Body)
    if ioerr != nil {
        log.Println(ioerr)
        fmt.Fprintf(w, "IO Error (Response body)")
        return
    }

    w.Header().Set("Content-Type", resp.Header.Get("Content-Type"))
    w.WriteHeader(resp.StatusCode)

    fmt.Fprintf(w, string(body))
}

Answer 1

Managed to solve this now! Thanks to Steffen Ullrich for pointing out the the issue could be "about compressed content". Removing the Accept-Encoding header as mentioned here worked like a charm.

...
// if you manually set the Accept-Encoding request header, than gzipped response will not automatically decompressed
req.Header.Del("Accept-Encoding")

freq.Header = req.Header
...