Note:
This step can be skipped if you are installing for the first time.
Download bedrive-flutter.zip file from CodeCanyon and extract it.
Copy/Paste contents of bedrive-flutter/lib folder into your own project and override the old files.
Replace old bedrive-flutter/pubspec.lock, bedrive-flutter/pubspec.yaml and bedrive-flutter/android/app/src/main/kotlin/com/vebto/bedrive/Application.kt file with the ones from the update.
Run flutter clean then flutter upgrade and flutter pub get commands. These can either be run from terminal or via android studio / vscode tools -> flutter menu.
Follow Android and iOS guides again to rebuild the apps and re-upload to app stores.