Ok, so this is a bit technical, but bear with me…
Thinkific does not actually support the selling of physical products through it’s checkout system. However, you can sell physical products alongside your course as part of a bundle, or as an upsell…
There are two ways to do this. You can create a course named “How to receive your [product name]” and then set the pricing as usual. Then, within this course, you can include a form for collecting the customer's shipping address.
The other way is to use a third party storefront, by installing Thinkific’s Shopify App.
Moreover, Thinkific also does not support the selling of digital products either such as ebooks or audiobooks to go along with your course…
But, there is a way around this. You can sell ebooks with the Groundhogg Thinkific extension from WooNinja, all without any third party software. But, this is not a free to use extension,