You'll see your new placeholder packs listed under Products >>>> All Packs. You can edit them with the desired supplements. please be advised that your designs only allow 1 uniform Time of Administration (ToA) so make sure all products have the same one, generally the default is Morning. Additionally, you can put up to 8 pills in a single pouch.
Once you have finished editing your packs, you can navigate to the Connection Settings section and select Edit>>>> Product List >>>> + Add Packs button and you'll be able to sync the new products to your Shopify store.