First accessing paypal.com with your data
Enter the profile menu--> more options
Within the more options menu go to the options menu
Within the API access menu click change
Click view signature API
Be careful when you copy and paste data and check that all data have been copied correctly in your Paypal, this module configuration form will prevent the 10002 error when using the module.
Paypal payment module for Prestashop 1.5 surcharge
Module Paypal surcharge for Prestashop 1.5 allows you to charge a fee when customers use Paypal or Paypal payment option Express.
Paypal payment module with surcharge for Prestashop
With this module you will allow your customers to pay for their purchases using Paypal and you can also configure how to charge them the surcharge applied by Paypal.