Unsupported upgrade request

[stplatt]

I installed this as a home assistant addon but after starting it up the WebUI shows only the text "Unsupported upgrade request".

Here's the log:

2022-08-15 13:06:56.439 | INFO     | __main__:<module>:48 - OS: posix
2022-08-15 13:06:56.441 | DEBUG    | __main__:get_env_ip_list:71 - Environement discovered IP List []
2022-08-15 13:06:56.444 | DEBUG    | __main__:get_local_ip_list:64 - Locally discovered IP List ['removed for security']
2022-08-15 13:06:56.444 | INFO     | __main__:<module>:126 - Broadlink will try to discover devices on the following IP interfaces: ['removed for security']
2022-08-15 13:06:56.445 | INFO     | __main__:<module>:135 - Configuring app
2022-08-15 13:06:56.447 | INFO     | __main__:get_analytics_code:179 - Content: <script async src="https://www.googletagmanager.com/gtag/js?id=UA-131664523-2"></script>
    <script>
        window.dataLayer = window.dataLayer || [];
        function gtag() { dataLayer.push(arguments); }
        gtag('js', new Date());
        gtag('config', 'UA-131664523-2');
    </script>
2022-08-15 13:06:56.455 | INFO     | __main__:<module>:652 - Broadllink Manager is up and running
INFO:     Started server process [7]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:7020 (Press CTRL+C to quit)
WARNING:  Unsupported upgrade request.
WARNING:  No supported WebSocket library detected. Please use 'pip install uvicorn[standard]', or install 'websockets' or 'wsproto' manually.
WARNING:  Unsupported upgrade request.
WARNING:  No supported WebSocket library detected. Please use 'pip install uvicorn[standard]', or install 'websockets' or 'wsproto' manually.