Coupon not found
Admin coupon API returned 404 Coupon not found. for update/delete by id (/api/admin/checkout-coupons/[id]).
Why this happens
Stale admin UI after delete, wrong id, or coupon already removed. Distinct from member Coupon code is not valid (apply by code string).
Diagnose and fix
1. Refresh the coupons list; open the coupon again from search.
2. If it was deleted, recreate it (watch for A coupon with this code already exists).
3. Confirm you are on the correct site/database.
4. Members never see this exact string for apply — they see invalid/apply-failed messages.