Please, follow the next steps:
0- Make sure that you have installed Google Drive app (or your cloud provider) on your device and configured to use it on iOS Files app
1- Open the Files app on your device and tap the "On my iPad" location
2- Browse to the "Notes Writer" app folder
3- Search for your documents then tap the "Select" button and select your notes
4- Tap "Share" button on the bottom toolbar then tap the "Drive" icon (or Dropbox or other) and send your documents! ;)
Hope this helps!
Notes Writer Team