Delivery to the door at unit in apartment

I deliver for doordash and drop the food and groceries to customer’s unit in apartment. Today i entered the apartment by pressing the buzz code and customer unlocked door for me from upstairs. But in lobby the concierge lady ( don’t want to name her) stopped me and asked me to drop the food in lobby and told me as per the law no delivery person is allowed to go up. If I drop the food when customer has clearly mentioned to deliver their doorstep, they will give me negative review and reduce the tip, and the concierge lady threatened me to call cops on me for trespassing the private property. Anyhow I left the food in lobby. I don’t know the exact law here. Do you think the lady was right?