During a break, a schedule or lessons, or within 15 minutes of one starting or of the end of the “Daily limit” or the time you gave, the child's “Today” screen shows “Ask for time”. When time has run out the block screen has “Ask for more time”. You get a notification, and on “Home” the request with “15 min”, “30 min”, “1 hour” or “Decline”. If the time ran out in one app, the answer is “+15 min” or “+30 min” in that app only, on all the child's devices.
The request disappears by itself once it is no longer current: a new day has started, a break began, time was already given or the limit was changed.