Hi Scott!
There’s a few ways to connect your app to Zapier.
Let’s start with the most important question - does your internal app have an API and would we be able to connect to it on the web? If so, you could go ahead and create a private integration for your app here:
https://zapier.com/developer/documentation/v2/app-dev-guide/
If the app does not have an API, does the information get to a place where we could access it on the web, for example, sent to an email or able to be sent to a webhook? If yes, take a look at this blog post:
https://zapier.com/blog/add-any-app-to-zapier/
Hope that helps!