How is the daily mileage indicator placed on NULL at the AID?

Hello dear forum, can someone please explain briefly and clearly how the day-kilometre display (trip) is set to zero with the Active Info Display of the T-ROC, e.g. after refueling, since a simple zero-point button is obviously not available. Or does this happen automatically? Unfortunately, I have no idea about this so far. I have not yet received a delivery of my vehicle and therefore no operating instructions from which this might come. Another question e would like to ask: How can I, for example, limit the opening angle of the electric tailgate in a low garage, so that it does not strike at the open garage door at the top? (Setting or programming?). I would be grateful for a short and clear answer from you, because I am very concerned about this.