Want my package left at post office because I forgot to put apt number

[andyinbusiness]

I called Fedex and asked if they can leave my package at their post office and they said they are not allowed to unless the shipper allows it. So I contacted my seller 3 times and he has never responded once in a span of a couple days. I'm not sure what to do because if the item gets shipped to my address it will not be delivered to me because I forgot to add in the apt number. What should I do?