-Go to ( uber.com/gift-cards ) then follow bellow :
1-Make sure you have the latest version of the Eats app.
2-Tap the menu Account tab and select “Wallet.”
3-Tap “Add Payment Method” and select “Gift Card.”
4-Enter your gift code (no spaces).
Once a gift card is added to an Uber account, it can’t be transferred.
You can’t reload a gift card, but you can continue to add up to $1,000 in gift card credits to your account.