https://woocommerce.com/products/woocommerce-checkout-add-ons/

Easily Offer Free or Paid Add-ons and Services at CheckoutAdd option fields for add-on services and products (without inventory management)Optionally add costs for fields or selected optionsUse amount or percentage-based feesApply costs on a per-option basisDynamically update the order details and total on the checkout page as options are selected or changedSaves selected options & uploads even if customers browse away from checkout!Supports WooCommerce Subscriptions – A checkout add-on will add a one time charge to the initial purchaseAllow admins and customers to view order add-onsSupports One Page CheckoutOptionally view new fields from the “Orders” pageOptionally sort or filter orders based on new fields

Changelog

* Misc - Add admin notices to help merchants reverting to the cart or checkout shortcodes if the corresponding blocks are used instead