Guys, if you're all wondering why it doesn't show up: back in the day, you had seperate editions for seperate consoles. Ps4 got a Ps4 edition, Xbox got an Xbox edition and so, Switch got a Switch edition. The problem is: Somewhere in 2019, minecraft merged all these editions togheter into bedrock, so crossplay between these consoles would be possible. In order to make that possible they had to remove all the seperate editions from the stores and replace that with the 1 game called 'Minecraft Bedrock'. And with that, all the mashup packs would be gone too, including this one. But if your copy of the game is older than 2019 and it got the name "Minecraft ... edition", you can still access them. When you have the main menu at the start of the game, there should be a button on the bottom that says something like "Editions". And if you have the Switch or Wiiu version of it, this mashup pack should be there. That's why this person was still able to play it. Damn you've made it all the way through😂 thanks for reading
Go into the create world option, and then it should show like downloaded maps you have, select this one, if you have it, and then just create a world from there.