How to Download Amazon App store Apks? topic

I'm in a stupid situation. The few app purchases I've made on Amazon's app store were made on a different Amazon account than my current Amazon prime account. Is there a way to download the apk for an Amazon app store app which I purchased previously so I can side load it on to my FireTV Stick?

I've been able to side load apps from the Google Play Store just fine but how do you download an apk (the version specifically meant for FireTV stick) of a paid app you purchased on Amazon's app store? Any help is much appreciated.