This is when you choose your partner for accepting credit card payments. Typical partners are Stripe, PayPal and Authorize.net, or if you’re using Shopify: Shopify Payments. Look into the fees for these, see their features and what works best for you, but also, keep in mind what your customers will be expecting or feel most comfortable with.
It is possible to have more than one form of payment set up on your site if you wish, but it does tend to complicate things in the check out so we don’t usually recommend it.
Put through some test orders to make sure you are comfortable with and knowledgeable about how payment works before launch!