At the customer’s door, you can tap Arrived in the rider app to alert them that you’ve arrived. 

If you can’t reach them, you can send them a message through customer chat or call in the rider app. In the rider app, tap Order > Order details > Contact options. 

After some time, you can send a Leaving Soon alert. 

If you still haven’t heard from the customer, you can tap Complete the Order and leave the food in a safe place, and inform the customer where you’ve left the order through customer chat in the rider app.