PDF Viewer allows you to seamlessly access and sync data in the "PDF Viewer" folder in your iCloud. To open files that are stored inside iCloud Drive but are not inside the PDF Viewer folder, there are several options available:
- Open the file from its original location. Changes made in PDF Viewer will modify the original file: Open the iCloud Drive app, select the file you want to see in PDF Viewer, tap the action icon in the lower left corner and select 'Open in PDF Viewer' from the middle row. This will open the file in PDF Viewer but keep it on iCloud Drive. So when modifying this file it will be saved back to iCloud Drive.
- Importing the file into PDF Viewer, creating a copy of it: Open PDF Viewer, select the plus icon on the lower left, and then select iCloud Drive. Select the file you want to import. This will create a copy of the file, changes you make to the file will stay inside PDF Viewer but will not be synced back to the original file.
You can also access files on your Mac and simply move the files into the "PDF Viewer" folder.
If the folder doesn't appear for you, please see our Troubleshooting iCloud Drive article.