Creators often want to try a product before marketing them to their hard-earned audience. They also need the product to created content. When a creator requests a product sample, they opt in to sharing their address with you.
When you approve their product sample request on the Orders tab of Social Selling, two things happen:
An order is created in your Shopify admin with a 100% discount applied. You can fulfill this order just like normal --- the address is already filled
The creator receives an email with instructions for what to do next and with tracking information