Sending a key event to grafana in an iFrame

We’re displaying a grafana dashboard in an iFrame with kiosk settings (because we want to hide potentially destructive controls from the user). However, this also hides the zoom out button. When a user has zoomed in by selecting an area inside a graph with the mouse, we want to enable zooming out again. For that purpose I implement a button (outside the iFrame) that should trigger the Crtrl-Z key combo in the iFrame.
I can see that the event is registered inside the dashboard code (in mousetrap.js), but the zoom action is not performed. When I manually use the Ctrl-Z keydown in the iFrame it does work.
One difference I can see between the regular keydown event and our generated event is the isTrusted field, which is false in our generated event.
Is there an example that accomplishes something akin to what I’m trying to do?