How to use pick_asset from the photos module?

I use the App Python Offline.

I tried to use photos module.

import photos
assets = photos.pick_asset(title='Pick some assets', multi=True)
print(assets)

I got this error: AttributeError: 'module' object has no attribute 'pick_asset'

https://itunes.apple.com/fr/app/python-offline/id1351388468?mt=8

http://omz-software.com/pythonista/docs/ios/photos.html

from How to use pick_asset from the photos module?