Error connecting to WebSocket


I’m trying to test a websocket connection via Postman however I’m running into an issue:
Error: getaddrinfo ENOTFOUND {server-url}

My handshake details are:
Request URL: {server-url}

Request Method: GET

Request Headers

Sec-WebSocket-Version: 13

Sec-WebSocket-Key: y9ZjCcnMMM3xrpVUg2xORg==

Connection: Upgrade

Upgrade: websocket

Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits

Host: {server-url}

I’ve tried it with connecting to my VPN and without VPN, and disabling proxy but it still does not work. I can confirm the server is working as I’ve used an online websocket tester