WebSocket Notification API: How to subscribe to conversation events?

What’s the right way to subscribe to conversation events via the Genesys Cloud WebSocket API? I’m using the JS SDK and trying to set up the subscription but not sure if I should use the REST endpoint or direct WebSocket connection. Here’s what I have so far:

const client = new PlatformClient.ApiClient();
client.loginBasic('user@example.com', 'password');
// Not sure how to proceed from here

Any help would be appreciated.