A bundle ID, or package name, is a unique identifier for your Android app. When publishing your app you can not use the same ID as an app that has already been published. For example, Thunkable Live uses the package name
There are a number of rules you must follow to create a valid bundle ID.
It must have at least two segments [one or more dots].
Each segment must start with a letter.
All characters must be alphanumeric or an underscore [a-zA-Z0-9_]
Here are a few examples of invalid bundle IDs:
This ID is invalid because it only contains one segment
While this ID does contain more than one segment, it is invalid because segment names must begin with a letter. In this case "2ndEdition" is not a valid segment so the entire ID is invalid.
This ID has three segments and each segment begins with a letter, however segments may only contain letter, numbers or the underscore
_ character. Since this bundle ID has a "!" and "@" it is not valid.
Changing your Package Name
In the drag and drop editor, click on "Settings" in the left bar and change the "App (Bundle) ID" property.
In the legacy editor, click on your app name in the component tree to open your project settings.
On the right hand side of the screen change the "App (Bundle) ID" property.