As cryptocurrencies are more and more popular, you may want to allow your customers to pay with Bitcoin, Litecoin, Dash or other crypto. Here are two examples of payment gateway services, that will allow you to easily implement cryptocurrencies in your store with their free Prestashop module. There are also standalone paid modules available on official addons portal, that allows to accept Bitcoin, Litecoin or Bitcoin Cash, without any 3rd party.
Supported cryptocurrencies: Bitcoin, Litecoin (in Beta)
Prestashop module on GitHub: https://github.com/bitcoinpay/bitcoinpay-prestashop
Bitcoinpay currently supports Bitcoin and Litecoin in Beta. There are no monthly fees, the transaction fee is 0.8%. It allows to instantly convert the payment into your local (fiat) currency and every payment has it's invoice in fiat, so there is no problem with accounting. Payments are deposited into your linked bank account or wallet each business day according to your preferences. They also have solution for retail stores - web based Point of Sale for mobile devices and more advanced App. LILKA Point of Sale.
NOWPayments is a non-custodial crypto payment gateway that lets you accept payments in 100+ cryptocurrencies. The auto coin conversion lets crypto customers pay with any coin —NOWPayments will convert them to the coins the merchants choose to accept. The platform also supports fiat conversion and offers customized solutions for Casino, Twitch donation button, and a Mass Payments solution. There are different tools available: API, invoices, donation widget, buttons, as well as plugins for PrestaShop, Opencart, WooCommerce, ZenCart, Shopify, WHMCS, Magento 2, and others.