def METHOD_NAME(self) -> payload.BytesPayload:
    # form data (x-www-form-urlencoded)
    data = []
    for type_options, _, value in self._fields:
        data.append((type_options["name"], value))
    charset = self._charset if self._charset is not None else "utf-8"
    if charset == "utf-8":
        content_type = "application/x-www-form-urlencoded"
    else:
        content_type = "application/x-www-form-urlencoded; " "charset=%s" % charset
    return payload.BytesPayload(
        urlencode(data, doseq=True, encoding=charset).encode(),
        content_type=content_type,
    )