Is it possible to add more query parameters in the event filters?

For the purpose of my RingCentral integration I need to create a webhook subscription and I subscribed to the following event:
/restapi/v1.0/account/{accountId}/extension/{extensionId}/message-store/instant?type=SMS
This works great and all incoming SMS messages trigger a webhook call.

I then looked at the page of the event.
https://developers.ringcentral.com/api-reference/Instant-Message-Event

Noticed that this event has some fields and for my next requirement I want to only listen to events that have certain subjects for example:
/restapi/v1.0/account/{accountId}/extension/{extensionId}/message-store/instant?type=SMS&subject=Hello

When trying to create a webhook subscription with this event filter the request failed.

Is there a way to achieve this with RingCentral?