Add Country in shipping list

Hi there!

I want to add some countries in the shipping list of Woocommerce, especially some regions like Portugal Islands or Corse in France.

I tried this code : https://docs.woocommerce.com/document/add-a-new-country-to-countries-list/

I tried to integrate “Corse” like a region of France but it didn’t work, it works well just like an European Country.
Moreover, I have few countries to add, but I didn’t manage to develop this code for many countries, do you have a solution?

Thank you a lot for your help !