Did you look at Firefox download page to see if there was a version for it.

''<p>mrsjh90 [[#question-1506548|said]]</p>'' <blockquote>Can I install Firefox on my Amazon fire </blockquote> You ''may'' be able to side load install the Firefox apk file onto the Amazon Fire tablet. Since there are multiple versions of the Fire tablet over the years I cannot say which would be best, perhaps android rm64-v8a/ or android-armeabi-v7a/ https://archive.mozilla.org/pub/fenix/releases/137.0.2/android/ Mozilla tried to host the android Firefox on the Amazon app store many many years ago however Amazon complicated things in changing the file which then affected getting updates.