Use terminal maps to plan your drop-off or pick-up point; some ride-hailing apps designate specific zones

https://telegra.ph/Heathrow-Airport-Shuttle-and-InterTerminal-Transfers-Whats-Free-and-When-08-17-2

Use terminal maps to plan your drop-off or pick-up point; some ride-hailing apps designate specific zones, and short-stay car parks are signed clearly.