Teach me how to make an Alpha Transperent Video Work on my Web

I've been pulling my hair out with adobe people trying to get someone at that company to show me exactly how to get my videos with full alpha channel backgrounds to play on the web. But it seems that The new Adobe Media Encoder wont encode for FLV anymore and the Adobe animate(flash) program won't import my alpha channel videos! And when I try to import any of my videos with alpha channels to the web they all have black backgrounds! So What I need is someone to write me EXACT Instructions (From The Beginning) on how to do ALL of this using Adobe 2018 products (Dreamweaver, After Effects, Media Encoder, Premiere) and also write me one well documented Html Page that actually shows that it works. I want to play One alpha transparent background Video on top of a Regular video. Right now my transparent video is just a man talking and the background is a video location. I will swap out my videos with yours when finished. To make sure that what I build works.