Can we trigger Attended Robots via an API call?
No, even though Robots can be triggered by making an API call to Orchestrator, attended Robots are intended only for direct triggers from the machines themselves. This would mean the Attended Robot cannot be triggered from Orchestrator, consequently API calls to trigger a Robot would not be possible.
The only alternative available to trigger Robots apart from the Robot tray is by using the command prompt. For more details on this procedure, reference is available on the list of arguments that go along with UiRobot.exe, which can be checked on this article. Do note that even though triggering a Robot is possible, doing it via Windows Task Scheduler is not supported considering the type of Robot used is Attended Robot.