The Files app on the iPad is a place to easily organize files stored on all your iOS devices, iCloud Drive or supported third-party apps. To access files stored on other apps, like Google Drive, you need to enable each app in the Files app. Here's how:
- Open the Folders app on your device.
- Navigate to Browse.
- Tap the Edit button.
- Tap the slider next to the third-party app you would like to add.
Now you will be able to access or search all files stored on the selected third-party app in the Files app. Third-party files will also be available across all synced iOS devices.