Taping an envelope to your door clearly visible for the delivery person would still remain contactless. If the envelope is still there when you pick up your items, then no harm in trying
/s but only kind of.
(well, not my UPS guy, he's actually a she, and she gives my dogs treats when she sees him)
People steal Amazon packages regularly, I think they would not hesitate to steal something that says "Instacart" on it.