Dear,
Last years, the delivery platform 'sendmyparcel' has become very popular, especially in Belgium and the Netherlands.
This platform is supported by many systems, but unfortunately not on Joomshopping.
The developers have a free API available, see https://myparcelbe.github.io/api/
Can you develop an add-on for this delivery platform?
Keep in mind that you can use multiple carriers on this platform and that there are restrictions in terms of size and weight and there are different prices.
If needed you can create a test account https://backoffice.sendmyparcel.be/registration and they can help you with the development.
Best regards,