Free $5-$10 Xbox / Microsoft USD Gift Card (YMMV) – Check Xbox Messages

Check Your Xbox Console or Xbox Mobile App for the Message:
Xbox Live
Spring Sale starts today! Here is a special gift to help you make your first game purchase. Enjoy this $10 USD Gift Card you can use to buy Games, Add-ons, and Movies on your Microsoft Store online.
Redeem your gift card on console or Xbox.com/RedeemCode by 4/30/2021 and spend within 90 days of redemption. See full terms at Microsoft.com/CardTerms
As usual in the past this is YMMV and can vary in amount.
Redeem codes here Microsoft/ Xbox Code Redemption
FYI. You can redeem now if you need it, otherwise you may want to wait until 4/29/2021 to give yourself an extra month, total 4 months, before the balance expires.