Upsell in a Form

How to organize additional sale in GetCourse form?
In setting of block with form with an offer add “Offer an addition” option, fill in “Title” and “Text” fields with information about an offer, choose it in a list or create a new one.

It is required to have user authorization with “Full authorization, ask for user's password” flag in a form handler.

After filling in a form information about additional offer appears. In case if a user gives a consent, this additional position will be added to an order. If a user clicks on “Skip” button, then redirect to purchase page will be performed. A user will purchase only the first offer.

If you want to set up more complicated chain of upsells and cross-sells, check this guide.