I’ve done extensive research, and what I’ve found so far is that, according to Chrome’s policies (as well as most other browsers), it’s impossible to play a sound on a website without user interaction (such as a click).
There are solutions based on exploits (which have stopped working), bugs, etc., but according to browser policies, videos can only autoplay without sound. However, YouTube essentially bypasses this rule and plays both video and audio automatically when a page loads. That being said:
What is the explanation?
Does YouTube have special permissions because it’s YouTube?
What is the necessary HTML/JS code to achieve the same result and autoplay video audio when the page loads?