Where is the flutter asset bundle located?

The docs say

During a build, Flutter places assets into a special archive called the asset bundle, which apps can read from at runtime.

If I want to refer to the assets folder in places like webviews, I can't do that since I don't know the path of the asset folder on device.

I tried the file:///android_assets url but that doesn't work.

Specifically, I am looking to get this working.