You could have the person doing the knocking compare it when they arrive at the location.

The more practical solution (excluding just using a normal alarm) would probably just sending a OTP to the address that needs to be entered before the first order.

Alternatively (not sure if this is available in the US, just basing this on the German ID cards), you could use the person's eID to verify their address. This is probably a bit too complex for a fun project like this one though.