http RAW can take optional data body.

upload.go

 }
 
 func httpRaw(httpMethod, targetURL string, data []byte, headers map[string]string) (resp string, err error) {
-	req, err := http.NewRequest(httpMethod, targetURL, bytes.NewBuffer(data))
+	requestBody := io.Reader(nil)
+	if data != nil {
+		requestBody = bytes.NewBuffer(data)
+	}
+	req, err := http.NewRequest(httpMethod, targetURL, requestBody)
 	if err != nil {
 		return
 	}