It stays off until you turn it on in Settings. Your computer then
connects out to our relay and your phone talks to that relay, so it works
from any network, behind a key only your machine shows you. Scan the
code once in Settings, add the page to your home screen, and it stays
paired.
Every press is yours. Nothing here accepts a match on its
own. A person tapping from another room is remote control; a script
clicking for an empty chair is automation, and Riot bans the second one.
So there is no timer and no auto-accept, by design.