When Invoice is created in Billsby > Send a stream message in ZulipBillsby + Zulip IntegrationActivate
When Invoice is updated in Billsby > Check any condition > Send a stream message in ZulipBillsby + Zulip IntegrationActivate
When Subscription is updated in Billsby > Check any condition > Send a stream message in ZulipBillsby + Zulip IntegrationActivate