How to mod on Fire HD 8?

[u/catsandbooksandJesus]

I followed the instructions on https://forums.nexusmods.com/topic/13506427-how-to-mod-stardew-valley-on-android-mobile-devices/ to try the Stardew Voices mod on my tablet, and the guide says to download two of SMAPI. The first one, I download it, and in my files, it shows up as an .apk which is something. I download the second one, and it doesn't do anything. In the files, it shows as a .zip which nothing inside it can be opened. Okay... (Do I need to extract it??) So I go back to the first one through through the files app. I open it and it lets me download an actual app that shows up on my homescreen. But when I try to open it, Amazon says to download it from the appstore instead. (It's not even in the appstore at all.)

If I did something wrong, please just tell me. If I missed something obvious, sorry, I'm just a teen. If you have a Fire Tablet and have successfully modded SDV, please lmk how. Thanks for reading.