As others have said, the key code comes at the very last minute. In our case, we ended up sitting outside waiting for the email. After several calls to our host and a phone call to Airbnb, we finally got the code. However, small problem...apartment hadn't been cleaned. Greg worked hard to rectify the problem and got a cleaner in right away, but this did mean we were not able to check in for a few hours.
However, once this was all settled, we enjoyed our stay. The apartment was great in terms of location - walk everywhere and easy transit. Nicely updated unit but noisy between suites and single pane windows, so bring ear plugs. Keyless entry is convenient (when you are not locked out).