Tickets: make zendesk triggers channel specific?

[rowanseymour]

Currently using the API we're only able to setup triggers which fire for any ticket created via any channel integration. The condition looks like...

{
    "field": "via_id",
    "operator": "is",
    "value": "55"
}

In the UI now however you can filter based on the specific integration..

{
    "field": "via_subtype_id",
    "operator": "is",
    "value": "55:360000089993"
}

but there's no documentation about that at https://developer.zendesk.com/rest_api/docs/support/triggers#create-trigger and am not seeing anywhere to get that 360000089993 internal id.