At this point, most labs don't ship overseas. However, some labs ship from the US to Canada- please check with your lab if they offer that option.
If you would like to send your products abroad, you can do this through Reshipment. Here, the lab will send the orders that need to be sent abroad directly to you, and you will then ship the products to your customers. You also have the option to charge your customers extra to send the products abroad.
You can set this feature up in Settings > Sale Settings > Shipping settings.
That's how it looks on the customer's end