The WebSocket request or response contained unsupported header(s).

[adityagalanga]

Hello there!
I'm using this plugin for my project, and then I get errors when using 'ws' and 'wss'.
When I use ws , the socket is stable and working. But when I change it to wss , socket gives response error like this

Error : The WebSocket request or response contains an unsupported header.
Close : Abnormal

is there something wrong with the socket ? or something wrong with my wss server ?
i dont know how to fix this, because i cant get more log for this error.

Thank you !

[edit]
Im using Unity 2020.3.2f1 free
And im already check another plugin, and its work when add this on another plugin code

ws.SslConfiguration.EnabledSslProtocols = SslProtocolsExtensions.Tls12

But how to place this code to this plugin ?