After checkout completes (but before the customer reaches the Thank You page), Zen Upsell can show a one-click “add this too” offer that charges the customer’s already-saved payment method — no re-entering card details.

Features:

Post-purchase offers: pick a trigger product and an offer product, set a fixed or percentage discount, and priority when multiple offers match.
One-click accept, charged via the customer’s saved payment token on a tokenization-capable gateway (e.g. Stripe).
One unified Offers list (order bumps are now regular offers). Choose in Settings where offers appear: Cart page, Checkout page or Thank You page.
Basic analytics: views, accepts, declines, conversion rate, and revenue per offer.

Requires a WooCommerce payment gateway that supports saved-card tokenization (e.g. the official WooCommerce Stripe Gateway) for the one-click charge to actually run — without one, post-purchase offers are simply skipped and customers go straight to the normal Thank You page.

A server- or CDN-level full-page cache placed in front of PHP cannot be bypassed by any plugin setting; if your host caches pages before WordPress runs, exclude the offer page URL pattern manually.