When using Splashtop Android App on a Chromebook to connect into a Mac/Win streamer, you may not be able to send a Cmd/Win key to remote side, since there's no such keys on Chromebook physical keyboard. In this case, you can choose to use the virtual keyboard or enable the keyboard setting option of this:
- With Mac Streamer:
- With Windows Streamer:
After enabling this option, you can use the Ctrl key on you Chromebook physical keyboard to map cmd/win key of your streamer side.