Unfortunately we were unable to check into this place and had to go check into a hotel down the street. After arriving in the afternoon, the check in guide did not have the lock box code we needed to get the key. I tried for 2 hours to contact the hosts via Airbnb, phone calls, sms and whastapp and got nothing (despite seeing that my messages in whatsapp had been viewed).
It was only after I had spoken with Airbnb to cancel the reservation that the hosts contacted me. Instead of acknowledging that the lock box code was not in the guide, they resent an edited version of the guide with the code now included. They were trying to offer me a discount on the first night for the inconvenience, but two hours late was too little too late for us as we had already organised other accommodation.
Hopefully now that the code is in the guide others won't have the same problem as the apartment is in a great location.