Email from UBER enter on Payment page by Promo codes. It worked with both of my accounts including the one I did not get an email from
see below
Ride for 50% off this weekend in New York City
Whether you're headed to the beach or a barbecue, get there for less this weekend.
Enter promo code MDWNYC50 to score 50% off 2 rides between 7pm tonight and Monday, May 30.
OPEN THE APP
Once you enter code MDWNYC50, this promotion will apply to your next 2 rides in New York City after 7pm today (Thursday, May 26).
Rides must originate in New York City (Manhattan, Brooklyn, Bronx, Staten Island, Queens)
Valid between Thursday, May 26, 7pm ET, and Monday, May 30, 11:59pm ET
Max. value up to $25 off per ride (up to 2 rides)
Offer excludes uberT