When you transfer products from Shopify to Etsy, Shuttle can add the same production partners to every new Etsy listing it creates. You choose them once, so you don't have to add them to each listing by hand.
Production partners must exist in your Etsy shop first
Shuttle doesn't create production partners, so it can only use the ones already set up in your Etsy shop. The Production Partners section lists only those partners. If you haven't added any yet, add them in your Etsy shop settings first.
Choose your default production partners
In Shuttle, open Settings.
Under Products, choose Shopify → Etsy.
Scroll to the Production Partners section, or pick Production partners from the section list.
Under Available partners, tick each partner you want added to transferred listings. Untick a partner to remove it.
Click Save.
If the Production Partners section says "No production partners were found in your Etsy shop", add a production partner on Etsy first. The section keeps showing the old list until you reload, so reload Shuttle in your browser and open the Production Partners section again.
Which listings get your production partners?
Shuttle adds your selected production partners only when a transfer creates a new Etsy listing. Updating a listing that's already on Etsy doesn't change its production partners.
Change your production partners
You can change your selected production partners at any time, and the change applies to future transfers. Listings already on Etsy keep the partners they have, so to change those, edit the listing in Etsy.