errand_add_tip
Adds a tip to an already-placed errand order to encourage a faster pickup. A tip is its own separate payment order: this tool only returns a checkout link for the tip — the user must open it and complete payment before the tip takes effect and is added to the order’stip_fee. Only available before a rider accepts the order; you can call it multiple times to add tips incrementally.
Parameters
Returns
Calling this after the rider has accepted the order returns
ERRAND_TIP_NOT_ALLOWED; a tip_fee of 0 or less returns ERRAND_TIP_INVALID.
