Yes, you can send items with no contact information for the drop off location. Simply mention that there is no contact information for the drop off location and please give instructions as to where the item should be dropped off.
Every effort and steps will be taken to contact the person at the drop off location. If the person is not reachable the driver will contact the customer who place the order, if the customer is not reachable then the item will be taken back to the customer on the customers expense.
You need to contact Customer Support to update your order to change the status to no "signature upon delivery".