On modern browsers, using autoplay is hard. It gets blocked unless you enable hidden settings
To do this, either download the autoplay_enable.js, upload it to your own site and use that (better approach)
or include this code snippit that loads it from my site in the <head> (important) of your page(lazy):
It automatically seeks ot any <audio> tag with the autoplay attribute set, so you will not have to change anything. Just use the autoplay attribute as normal. It will not interfere with other JS that pauses/plays audio tags.
Audio on modern browsers will not be allowed to play, unless its activated by a user interaction like clicking, tapping, keyboard, etc.
The scripts triggers on all of those events and triggers the autoplaying ONCE. This is to not interfere with other JS.
I commented the script a bit so that you can understand it better.