@Ayzar247 you have to, once, give Pythonista access to your "on my iPad" folder in Files.
This is done via the open external, then folder, then select "on my iPad".
.

The choose the location

Then you will see this

And in your script, you will have access to a file by a path like

path = '/private/var/mobile/Containers/Shared/AppGroup/EF3F9065-AD98-4DE3-B5DB-21170E88B77F/File Provider Storage/Myfile.txt'

Where the EF3F9065-AD98-4DE3-B5DB-21170E88B77F part will be different for your device.
I still have to remember how to find this value...

Édit: create this script in this folder and run it

import sys print(sys.argv[0])