I have a very simple PHP & MySQL website. I want to include a payment system in my website, but there only local bank payments in Sweden.
Is there any built-in module? Any idea how much that costs?
There's nothing built in to PHP.
The first result for my Google search comes up with: api.payson.se
You need to integrate with a payment service provider. It's slightly more awkward since you're in Sweden, but a few popular options are: