The Offer processing option determines how your Offer will be processed in your billing system.
The direct Billing Integration is typically the easiest as it requires no custom development or manual workflows on your end. Webhooks and URL Redirects are viable options if you have development resources who can help assist with implementing them. Email can be a great option to get started if you don't have access to technical resources. Select the option that is best for you and then proceed into the Offer Editor to finish building out your Offer.