If you are looking for gameplay content like or Keys , these were built-in from the start in the 3DS version rather than being added in later patches like they were on the Wii U.
1.05 (Released March 23, 2021) Addressed an issue involving StreetPass functionality. Nintendo Support How to Update Super Mario Maker for Nintendo 3DS Super Mario Maker Update v1.05 3DS (EUR/JPN/USA...
: It was released on March 23, 2021 , specifically to maintain connectivity as other legacy services changed. If you are looking for gameplay content like