Follow these steps to upload your bundle
to the Play Store.

Build an APK

Although app bundles are preferred over APKs, there are stores
that don’t yet support app bundles. In this case, build a release
APK for each target ABI (Application Binary Interface).

If you completed the signing steps,
the APK will be signed.
At this point, you might consider obfuscating your Dart code
to make it more difficult to reverse engineer. Obfuscating
your code involves adding a couple flags to your build command.

From the command line:

Enter cd [project]

Run flutter build apk --split-per-abi
(The flutter build command defaults to --release.)

This command results in three APK files:

[project]/build/app/outputs/apk/release/app-armeabi-v7a-release.apk