To turn your Samsung TV on from the app while it is off, enable network wake-up on the TV.
- On the TV: Settings → General → Network → Expert settings.
- Turn on « Power On with Mobile » (depending on the model: « Remote start » or « Network Standby »).
The phone and the TV must stay on the same Wi-Fi. Leave the TV in standby (red light) rather than unplugging it, so its network stays awake.