I recall you commenting on one of our posts about your son playing Splatoon 1, I really hope he's able to play soon
For the moment, you need to install custom firmware to play Splatoon 1, linking official statement since not many people have been reporting on it (even us)
https://forum.pretendo.network/t/sssl-not-currently-working-on-wii-u/648
Not sure if you saw my reply regarding it, I'm just going to hold out for now until Lemmy gets updated to support authorised fetch, will cross-post our SFPK posting right now and it'll be up to the community to do the rest since I don't really use Lemmy as it is