PayPal Official module offers the possibility to accept payments by credit (or debit) card without using a PayPal account. This option is available for some countries and could be modified in the module configuration panel up to version 5.1.x.
Starting from version 5.2.x, it is no longer possible to force the activation or deactivation of payment by card via the module configuration (except for merchants with an account registered in Mexico or Brazil, that have a specific system for the payment by card).
Now this functionality should be managed directly in PayPal account configurations as explained in the official PayPal guide.
So, to receive guest checkout payments, login in your PayPal account then click on Seller Tools > Website preferences
Find the option “PayPal account optional” and Select “On”.
If you wish to accept card payments, you can also consider using the PrestaShop Checkout module.