ResourceWarning:unclosed transport (HABApp)

I have a little peace of code which downloads a website for further data analysis.

It seems to work as it should (I get all the data I need), but in the log I get always the message:
2022-09-10 20:47:08.725 [WARN ] [HABApp.Rule ] - /usr/lib/python3.9/asyncio/ ResourceWarning:unclosed transport <asyncio.sslproto._SSLProtocolTransport object at 0x72f20928>

What can I do to stop this warning?
How can I react on it and close the transport?

    async def ExtractLocalData(self):
        offizielle COVID-19 Daten aus Homepage extrahieren
        LOGGER = self.__class__.__name__ + ".ExtractLocalData "

        # Website einlesen
        URL = ""

        HTTPStruct = None
            async with self.async_http.get(URL, timeout=9) as resp:
                HTTPStruct = await resp.text()
        except asyncio.TimeoutError:
            self.log.error(LOGGER + "Timeout beim Holen der lokalen COVID-Daten")

        #     ResourceWarning:unclosed transport <asyncio.sslproto._SSLProtocolTransport object at 0x72fdd9b8>
        if HTTPStruct is None: