Nintendo Account and Nintendo Network ID Link Service Ends Next March

The service that allows users to link the Switch's Nintendo Account with the 3DS and Wii U Nintendo Network ID will cease on March 2024.

Nintendo Network down? Current problems and outages

How to Connect A Supervised Nintendo Switch Account to Epic Games

Nintendo's Wii U and 3DS online services will shut down in April - The Verge

Nintendo 3DS - Wikipedia

Nintendo eShop closing for 3DS, Wii U next year — Here's something you might want to do right now

Sorry if this isn't the right sub. How can someone tell if a 3ds is not authentic? : r/3DS

Nintendo is shutting down the Wii U and 3DS eShop in March 2023

Nintendo eShop closing for 3DS, Wii U next year — Here's something you might want to do right now

Wii U and 3DS Nintendo eShop sales to end on March 27, 2023 - Gematsu