@o4o @barretLoganj13 has beat me to it. Getting slow in my old age.

That is exactly how I installed the Google Play Store and Google Play Services. I found most apps work on both tablets but some apps on the Fire HD 8 Plus 2022 with Fire OS 8 give me an error saying I need to install the latest version for Play Services which is already installed. The same apps on the Fire 7 2019 with Fire OS 7 work fine with exactly the same version of Play Services. I fixed this by using an older version of those apps which gave me an error. Please remember that doing any of the above is done at your own risk. There are also options in settings on the Fire tablets to remove all the Amazon items on the home screen to make it more like stock Android. These settings just hide things and do not remove them from the device so you can easily reapply them if you wish.

@o4o If you are a wee bit tech savvy You can sideload the Google Play Store (requires 4 apps, Play Store, Google Play Services and 2 others) on Amazon Fire Tablets. Then install Opera or Opera Mini from the Playstore. I have done this on an Amazon Fire HD 8 Plus (2022) and an Amazon Fire 7 (2019). Just make sure you obtain the Files from a reputable source.

You could also just sideload the Opera or Opera Mini apk on it's own, again downloading from a reputable source.