Controlling flow from another flow (example)

I’ve been asked several times whether it’s possible to start/stop one flow from another flow. The answer is - Yes.
Here is the flow, that can be registered as a virtual device with on/off button in the app, and the button can be used to start and stop another flow.
After importing the flow, use Settings to configure target flow-id.



There is something wrong with this flow, I tried to import, change destinations flow ID, registered as virtual flow, but in the app, the slider is grayed out and not able to switch