Once nopCommerce has been installed, navigate to the Administration section of the site.
Navigate to Configuration > Plugins > All plugins and themes
Search for Zapper and download the plugin zip file.
Once downloaded go to Plugins > Local plugins and click the Upload plugin or theme button and select the zip file downloaded in the previous step.
Install the Zapper payment method plugin by selecting the Install button
Once the plugin is installed, select Configure from the Plugins screen and enter your Zapper Merchant ID and Site ID
Click Save to save your changes
The Zapper plugin is now configured and ready to be used as a payment method in the nopCommerce store