We don't support selling physical products through the Thinkific checkout, however we do have instructors selling physical products (kits, books, etc) alongside their courses as part of a bundle, or as an upsell in a couple of different ways!
If you are managing your own shipping and handling, you can still take payment through Thinkific if you would like. You would need to create a course named something like 'How to receive your [product name]' and then set the pricing as usual. Within this course, you can include a survey or another kind of form (e.g. a Typeform) for collecting the customer's shipping address.
Alternatively, if you have a platform that is handling your shipping, you could embed a button from another payment service onto your landing page or link your buy buttons to an external checkout link.