Hello, Adam. Webhooks lets you receive event-triggered callbacks for entities that your application needs to stay on top of. This app also notifies you automatically whenever data changes in your end-user’s QuickBooks Online company files. 

In your case, matching your bank transactions will trigger Webhooks regardless if it's payment or bill payment, as long as there are modifications done. Nonetheless, I suggest reaching out to them directly. They'll be able to provide you with additional details if there are any necessary actions or requirements for the trigger to occur. Here's how: 

1. Log on to the Intuit Developers webpage.
2. Click on QuickBooks Desktop under What do you need help with?.
3. Pick Ask a Question.
4. Sign into your existing Intuit Developer Account or create a new one.
5. Type in your concern.
6. Click on Ask.

If you're all set, visit this extra guide about personalising sales forms: Customise invoices, estimates, and sales receipts in QuickBooks Online.

Keep in touch so wacnt herlp youf ruether with this matter or QuickBooks. Stay safe always!!