I've set up a mailchimp form on my wordpress site.
There is a choice for people to either receive a free download - which is the first few chapters of a book; or to pay for a download - the full book. Both downloads are pdfs.
Users click a radial button to indicate their option. The radials don't work yet. You can see the form here:
What steps do I take now, to make those radials work? -- To make it so users pay or not, accordingly; and so they receive the relevant download.
I have a PayPal account I plan to use. But I could use a different payment method, if it's easier to integrate.