Try "MYTENOFF" as a code for 10% off to save up to $50 through 3/31/19. It may or may not work. I didn't login and it showed up in the banner at the top of the eBay website (not in an email). It's both for the app and the website.
How to redeem your Coupon:
Shop for eligible items. (See below for exclusions).
Enter the Coupon code in the redemption code field: MYTENOFF
Pay for your item by 11:59 PM Pacific Time on March 31, 2019.
Terms & Conditions:
The Coupon is a 10% discount off, valid from March 13, 2019 at 6:00 AM Pacific Time until March 31, 2019 at 11:59 PM Pacific Time. No minimum purchase required. The Coupon discount is capped at a maximum value of $50. Discount applies to the purchase price (excluding shipping, handling, and taxes) of eligible items on eBay.com, cafr.ebay.ca and ebay.ca. Eligible items exclude warranties and protection plans, as well as items from the Coins & Paper Money, Gift Cards & Coupons, Vehicles in eBay Motors, and Real Estate categories. Coupon must be used within a single transaction (and can include multiple eligible items), while supplies last. Max one redemption per user.