This is an accepted solution.
Hi, @RainMakrLdn; Welcome to the Community. Great question!
The countries that appear as choices in your checkout for your customers Shipping Address are determined by the countries you include in your shipping zones that are set up in ‘Settings > Shipping and delivery’. Therefore, you need to edit your shipping zones and remove the countries you don’t want to be in the Shipping Address dropdown. Needless to say, only customers located in the countries within your shipping zones will be able to complete a purchase on your store.
Additionally, it’s not possible to limit the countries that show up when your customers are entering their Billing Address. The Billing Address is used to verify the customer's credit card information, and is not necessarily related to shipping. Therefore, all countries must always be available in the Billing Address form, regardless of the shipping zones configured in your admin.
Let me know if this helps!