If you have already set the shipping zone and market correctly but still can't ship to the address you entered, there are a few possible reasons for this error message:
The shipping carrier you have selected doesn't ship to the destination country or region.
The shipping rates or delivery options you have set up for the destination are not valid or available.
The customer's address is incomplete or invalid, and the shipping carrier cannot deliver to the address.
To resolve this issue, you can try the following:
Check if the shipping carrier you have selected can deliver to the destination country or region. You can contact the carrier directly or consult their website for more information.
Review your shipping rates and delivery options for the destination. Make sure they are valid and available for the customer's address.
Check if the customer's address is complete and correct. You can verify the address with the customer or use a third-party address verification tool to ensure accuracy.
If none of the above steps resolve the issue, you can contact Shopify support for further assistance. They can help you troubleshoot the issue and identify any potential issues with your account or settings.