Regarding the issue with entering the additional content, please review the following information:
■ Please verify that there are no errors in the characters entered for the "Download Number."
■ Confirm that the "Download Number" has not expired.
Please note that during maintenance or in case of issues with the Nintendo network, you may encounter difficulties in entering the download number. For information on Nintendo network maintenance and issues, please refer to the following link (you will be redirected to the Nintendo website): https://www.nintendo.co.jp/netinfo/en_US/
■ Ensure that the country or region of the game matches the country or region of your Nintendo Account.
If you have used a "Nintendo Account" registered in a different country or region to input a "Download Number" intended for use within Japan, you may encounter issues using the "Download Number."
If these steps do not resolve the issue, please feel free to contact us for further assistance.