Is it possible to do android mobile test automation without an .apk file?

I am creating android mobile test automation using a local appium server and I want to be able to test an application that is currently downloaded on the android device. I do not have access to the apk file for this application but the app is already installed, I just need to be able to access it. What would I need to do to create automation without the apk file because TestComplete prompts you to enter the location of where the file is stored?