If you want Dropified to automatically select a specific shipping method for all orders during the auto ordering process, you can set that option in Dropified Settings here. https://app.dropified.com/settings
However, you can also preset specific shipping methods for each product and variant in Dropified. You can even get more granular and use a different supplier and their shipping methods for each variant of a product in Dropified. The shipping method can be mapped per product and per country as well.
Dropified will then know which shipping method to use for each country order depending on the variant that is ordered.
Find this option under Variant Mapping > Advanced for any connected product in Dropified:
Update variants in Bulk
By ticking this option, you can bulk update all variants to use this shipping rule: