My neighbor hasn’t collected their parcel - what should I do?

I took in a parcel for my neighbor last week, but she still hasn’t come to collect it. I’ve knocked a few times when it seems like someone is home (lights and TV are on), but no one answers. She also has a doorbell camera, so it’s pretty clear that I’ve been trying to return her package.

Would putting a note through the door be the best approach, or does that come across as passive-aggressive? Any other suggestions?