PayFast is a South African based payment gateway which gives the ability to generate payment buttons which you can embed into your website.
These buttons can be generated in the PayFast dashboard, but we have used these to expand and personalise slightly for our clients here are some examples
One restriction is that NONE of these examples can allow for multiple item be added to any type of basket or cart, your customers will need to order and pay/checkout for one "product/item" at a time
Custom Amount Form
Can be used for Donations for an NPO or as a general payment amount
Popup with Order form
Can be used for Single Item Purchases
List of Items for Purchase with
List of services with totalizer
If you give us some more info on your need we can look into it and advise