You can only stop the session via the Shell App.
Open the screen showing your active session.
If needed, tap the icon for ‘minimised session’ at the bottom left.
To stop:
Tap the active session at the top of the screen
Tap ‘Stop session’
Wait ~10 seconds for the session to end
A message confirms the session has stopped
The LED light on the charge point changes colour
A cost summary appears on your screen – your session is now complete.