Shipping Profiles are created directly on Etsy
Log into your store, and highlight Your Shop, then choose Listings, then Shipping Profiles.
From there, you can click the Create shipping profile button to create a new shipping profile.
Please note that Etsy has not made Calculated Shipping profiles available to third-party solutions, like Sellbrite. You may only use Flat Rate (Set my own) shipping options.
Once saved, go to your Sellbrite account and refresh the Shipping Profile options in the Listing Builder.