From the official announcement:
On Friday, August 11 starting at 11:00am, open the Uber app and tap to request Ice Cream.
If matched, we’ll send ice cream to you and up to four friends. You’ll also receive a limited edition, collectible cone. Limited edition means limited supplies. So if you’re not matched, keep trying!
Take your collectible cone and punch card to participating McDonald’s® restaurants for one free soft serve every Friday from August 11 until September 22.
The promotion is available in 10 cities: