I´m having the same issue. It makes me think that this Websocket library will only work with the provided server.
I wrote a few lines of code to connect via Websocket to wss://demos.kaazing.com/echo , which is a server that echoes the strings that are sent to it. I was able to confirm the connection, and send some strings, but I don´t know how to read it when received. Same thing for other servers, like Loriot.