Can't get the key to unlock the door because car battery is dead

There should be a key hole in the door by the shaved door handles, just like the trunk does.They front doors should have them. Sometimes this key holes don't work so try to get some kind of lubrication should free it up after a while. Just make sure to wipe off any excess as it will destroy the paint. If all else fails open the trunk and try to crawl through the cut out or find out if the seat fold down through the trunk, I believe these don't so you are going to have to find someone to fit through the cut out and unlock the door from the inside. Hope you get in

Dead battery is not the problem. It's the key or the lick

The key is a manual door unlocking system. So no, a dead battery would not cause the door to not unlock with the key. A manual lock is absolutely necessary as a back up in the event of a power failure

Lube lock with grafite powder, as it won't freeze. If key still operates ignition, your key is likely just fine. Lube the lock