The Non-stored qualifier keeps an action active only while its parent step is active.
N is the default qualifier. If you do not specify a qualifier, AutomationView assumes N.
{GIF:HERE} - Step properties panel showing the action 'Motor running' with qualifier dropdown set to 'N' (Non-stored), no duration field visible since N requires no time parameter
from automation_machine import ActionQualifier
step.add_action("motor", "Motor running", qualifier=ActionQualifier.N)
Since N is the default qualifier, you can omit it entirely:
step.add_action("motor", "Motor running")
No duration parameter is needed.