On OpenCart, UndoPortal installs as a free extension: upload the .ocmod package for your version, paste your embed token, and a "Withdraw from a purchase" link appears in the customer account area — no theme editing or OCMOD refresh.
Separate builds for OpenCart 3.x and 4.x — install the package, enter your token, and you're done.
The "Withdraw from a purchase" link is added to the customer account area automatically, so customers can always find it.
The form matches your store languages, sends the durable-medium confirmation, and records every request in the audit trail.
Yes. There are separate .ocmod builds for OpenCart 3.x and 4.x — install the one that matches your store version.