Following comments, very likely only working on the Android app. Sorry for the inconvenience.
Just discovered an Uber Eats trick to get free delivery
I browsed the McDonald's menu and was put off by the £3.99 delivery fee. I then went to share a courier (below - available on app only, not website) and chose a restaurant offering free delivery.Important -
don't empty your basket from the previous restaurant when switching to one from the free delivery options and don't add anything when you choose a free delivery restaurant
I then left the restaurant menu offering free delivery without
adding anything to the free delivery restaurant. I returned to the McDonald's menu and the free delivery had transferred to the McDonald's order.
I was skeptical about the charge going through at full amount but I was charged the total without the £3.99 delivery fee applied