I'm not sure if it is AirBnb policy but a 3pm check-in is quite late.
For our arrival at 10.30 in the morning we paid an additional €10 euro to drop our bags and check-in. But we had to leave immediately and return after 3.
Happy that we could be accommodated -- but we questioned why we had to pay, why we had to then leave the apartment, and ultimately why the check-in time was so late in the afternoon.
That said - the apartment is very charming and well equipped. Super well located in a lovely part of the city. The bathroom needs an update (not surprising) and the bed headboard was disintegrating onto the sheets. Nothing really horrible as we were staying for just one night. Overall we were happy.