Can I use websocket in zoom apps?

Can I use websocket in zoom apps?

I have tried using pusher to see if websocket communication is possible within the zoom apps sample app, but I get the following error.

I looked up how to resolve this error and found that it seemed to be caught by the Content Sequrity Policy, so I wrote the following meta tag and tried to resolve the error.

<meta http-equiv="Content-Security-Policy" content="connect-src 'self'">

The following items are also added to the Domain Allow List.

If you know how I can use websocket with zoom apps, please let me know.