Thedocumentation only covers updating a schedule variable that was created. The only returned from create is

is aProjectPipelineScheduleVariable whereasschedule.attributes["variables"] returns a list containing dicts (see screenshot).

schedule.variables.create andschedule.variables.delete can be used directly but I'm unable to useschedule.variables.update directly.

What is the correct way? Also, will update fail if the variable does not exist or is it simply created?