World Export Issues

So, I'm trying to export a world that me and my friends were playing on, but there's no export button. I just updated the game to 1.21.100, and found a world I thought was lost. And I want to move it to my computer, but I can't find a way to download it. The device, if I'm remembering correctly, is an Amazon Fire Kindle 8th gen. I've had it since around 2013 at the earliest. It's barely holding on as is in terms of functionality. Any help is appreciated.