So, in my introduction, I mentioned that I wanted to speedrun Zelda A Link Between Worlds, but I don't have a way to capture any gameplay footage on my New 2DS XL. I do have a (standard) 2DS capture card from Katsukity before they shut down, but I don't remember where I placed the product key to activate it in the streaming software. What would you all recommend?

Mount a camera above you and point it at the console. There’s really no other option if you can’t use your capture card.