We arranged in advance with the hosts through Airbnb messages to check in at an earlier time since we arrived in Rome quite early after taking a 10h bus. We were not provided with check in instructions beforehand and when we got there the host was unresponsive. After an hour they finally answered their phone and let us know that there was a confusion of dates and we couldn't check in then since they had other guests in that room. We had to call Airbnb support and got a full refund after much explaining and we finally booked another place.