OPTION #1
SL: 🎈 Happy Birthday! 🎈
PH: Our birthday treat to you — enjoy a free dessert ToGo.
OPTION #2
SL: Your birthday treat is here!
PH: 🍰 Enjoy a free dessert ToGo.
OPTION #3
SLa: Sorry if we missed your birthday!
SLb: Wishing you a happy birthday!
PH: Enjoy a dessert ToGo on us to celebrate.