Service Bus + Azure function/ Invoke the function from WebAPI directly

Question

I have the following Azure function that runs on a CosmosDb Trigger. It takes a Document input and sends that data to another API. It works well but I have a couple of questions. The Document input/jsonData has a field called type. This type can be "Orders", "Invoices"... I want the AZ function to be run for insert statements with type="Invoices" I do not want the function to run for every insert or delete or update. How I configure it in such a way that the Function triggers only for type ="Invoices" and operation="Insert"