I appreciate your time posting here, @terry8.
Let me provide some insight into the triggers offered with our Zapier integration. Currently, the Zapier trigger when the invoice is paid in full is currently not supported.
To see all of the triggers we have available on Zapier, you can check out our app page on their site.
I also encourage you to visit our QuickBooks blog for new release features and updates.
Meanwhile, I'll be adding this to find out more about integrating QuickBooks Online with Zapier. Please check out How to Use QuickBooks and Zapier to Automate Your Business.
Just click the Reply button if you have additional questions. I'll get back to you as soon as I can. Have a blissful day ahead.