...and this is why we don't use Opencart anymore - client site has been compromised where the nefarious user added their own new fake payment method to checkout - Thankfully these types of things are easy to rectify and Astra (linked to their blog article that details the problem) has a great little inexpensive extension to help with that.

https://www.getastra.com/blog/911/credit-card-hack-prestashop-opencart-magento/