Go to the DQ store and buy something for the clerk to see. The clerk will take your mobile phone, enter your coupon number and password, and you can change it. It should be available in every store.

DQ is the acronym of Dairy Queen, which means "Dairy Queen". Its ancestor is American mccullough. 1938, American mccullough tried to make new ice cream products. Because the founder Mr. mccullough likes to call cows "the queen of dairy industry", the ice cream shop got its name. This is today's dairy queen.