Anyway, YMMV as they say:
1.Login to your Amazon account
2.Click this link:
https://www.amazon.com/gp/aw/promo/rede ... amazon.com
from your mobile device and click on the "Change your 1-Click setting" button to your Citi credit card and confirm it as your method of payment.
3.A $10 discount will appear on your next purchase of qualifying products shipped & sold by Amazon.com paid with your Citi card upon checkout