PostGraphiQL supports 'Subscriptions'?

Hi,
Not sure if I'm doing something wrong, but I'm testing Postgraphile with subscriptions and visualise through PostGraphiQL.
My query
```
subscription {
somethings {
edges {
node {
id
string
}}}}
```
executes correctly and I see correct data response. But when I create/update/delete a row, the changes do not get reflected in the PostGraphiQL response window.
The page says that the websocket connection is on:

Apologies, but I'm having hard time finding information on how to actually consume this subscription through postgraphile -> node(express) -> frontend (ie Axios, fetch etc). What chain of events (stack) would you use to deliver updated field value in database to user's browser html page?

Thanks in advance!