WebSockets not work with reverse proxy

[KatiaSisHost]

Hello, I am having problems with forwarding a reverse proxy from the domain back.example.com to ip 192.168.1.10 to port 3000

The web is sent correctly but it gives me a WebSockets error (it is a node app)

If I do it locally or if I send the domain to the ip 192.168.1.10 everything works correctly.

Does anyone have an example of a domain configuration file with websockets?

[KatiaSisHost]

Up**