In this documentation, we can check how to install payment module in Zen Cart.
1) Login to Zen Cart admin panel.
2) Go to the tab ‘Modules’.
3) Click the option ‘Payment’.
4) Select the payment module which you want to install.
5) Click the button ‘Install’.
6) Then you will get the new page to configure the module.
That is how we can install payment module in Zen Cart.
If you need any further assistance please contact our support department.