Android apps use package name as their unique identification. In some references, it may also be called Application ID. Although there are some differences between the two, for most of us non-developers, it is the same. It usually consists of 3 parts, but it can have 2 parts as well. For example, the package ID of Mozilla’s Firefox Browser for Android is org.mozilla.firefox.
Steps in Getting the Package Name of a Specific Application in the Google Play:
Step 1: Go to the Google Play on your browser.
Step 2: Search for the specific applications that you wanted to know.
Step3: Just copy the id in the end of URL of your visited application. Then you have now its package name.
Reference:
https://www.techmesto.com/find-android-app-package-name/