Job competition advice

Hello people of reddit, i need a little help. Recently due to the current virus epidemic my job has started to implement people to work in groups for our work shifts.

There are 3 groups which have four-five ppl in them. My problem is that my boss asked me to create a kind of competition/contest amongst the different groups. I have no idea of what type of contest that i can run between the groups, in a bit puzzled on this.

Some extra info is that i work for a coffee company. Most of the people that come into the store currently are mobile orders and pick up orders. Anything regarding up-selling and possibly sales might not work. Only because certain moments of the day offer a greater rush of customers then others and with mobile ordering we can’t control who comes in and what they order.

I’m thinking about something that’s possibly performance based among the groups. Any and all thoughts are welcomed.