How to set up a payment gateway in PrestaShop

Step 1: Log into your PrestaShop 1.5 dashboard.
Step 2: Using the top menu bar, hover over the Modules tab and click on the Modules option from the menu.
Step 3: You are now on the Modules list screen. On the left hand sidebar is a list of different module categories. Clicking a desired category will filter the modules seen on the right hand panel. You will want to find and click the one entitled Payments & Gateways.
Step 4: Once you have decided on which payment gateway you want to work with, press the Install button to the right to install the module. Again, part of your decision should be based on the fees that each payment processor charges.
Step 5: Once the module is installed, you may click on the Configure link to continue setting up the details for your chosen processor. Once configured, your processor should be ready to use.