Riders using Spare's rider app can apply the promo code from within the app.
Here is how!
Step 1 - Tap your account setting
Step 2 - Tap Promo in the account setting
Step 3 - Tap Enter promo code
Step 4 - Enter the promo code and tap Confirm
Now you have the promo and it will automatically applied to your next ride!! Have a good ride!