In this tutorial, we'll show you how to troubleshoot a standard .ppam add-in for Microsoft PowerPoint. This type of add-in is created in Visual Basic for Application (VBA) and may be debugged using Microsoft PowerPoint's built-in code editor. You will not be able to access the underlying source code if you activate a .ppam add-in in PowerPoint and then open the VBA code editor (Alt+F11). We will demonstrate how to modify the Windows Registry to be able to view the source code.

https://www.coragi.com/tips-and-tricks/microsoft-powerpoint/powerpoint-how-to-debug-a-powerpoint-add-in/