Create a private Zapier App

We have a web app that needs to be connected to several different CRM-systems, like Salesforce etc. Our own web app does not have an API and we don´t want to make one. Instead we want to create a private App on Zapier Developer Platform. [login to view URL] The trigger should come from about 5 different CRMs that are currently connected to Zapier. These CRMs should each have 2-3 different triggers (for example: new lead created, new sale created, new call created). The action of the app is an ordinary HTTP GET Request to a php-script in our web app. The GET request should look something like this: (example only) [login to view URL] The target end point (PHP script) will be managed by us.