To change Android ApplicationID for your app, please do the following:

Open the android/app/build.gradle file and replace the applicationID value with your own. See the screenshot below for an example:

Note 1: You need to replace your google-service.json file located in: /app/cirilla/android/app/google-services.json after changing the applicationID

Note2: The package name is for organizing source code only (similar to folders and subfolders on your computer). Changing it may cause errors.

• What is an Application ID?
• How to create file google-services.json?