Below you see a screenshot of the configuration on the settings page.
Here you can select the categories(s). Products in this category will have the options to set a individual payment gateway. THIS WILL NOT BE SHOWN BY PRODUCTS NOT IN THESE CATEGORIES.
The free version supports only 2 categories. So you can select MAX 2 categories. If you need more categories then we suggest to buy for a small price our premium version that supports UNLIMITED categories.
Default payment option:
If you add multiple products with all a different payment gateway then the system can not make the payments separately. It then will use the default payment option you wll set here by this option.