Carry out options

Ok so here’s a question I would like to put out here and would love everybody’s opinion and options. So going forward with possibly not being able to open my lobby, what options come this fall and winter do I have to get customers to let them know that their order is ready, to step up to the door/take out window, we have rain/sleet/snow coming this fall/winter we are in Mi and due to this covid-19 I cant have customers standing in the parking lot waiting. I’ve thought about a white board, and scrolling sign, just trying to get something figured out to plan ahead.