You can make your chosen candidate a formal offer for the role by clicking 'Make a formal offer' in their profile, once they've shown interest in a job. The button is on the right-hand side.
You will then see a confirmation pop-up. Click to confirm the offer.
If the role starts within the next 24h, the teacher's time to accept your formal offer is 90 seconds, if role starts between 24-48h, the time to accept a formal offer is 1h.
If the role starts more than 48h away, the time to accept is 6h.
If a teacher's offer times out, you are free to offer the role to another interested teacher. The teacher who timed out will have to reconfirm they are interested again before you can re-offer them the role.