In this article, we will walk you through the steps on how to enable video autoplay if it's disabled in the Google Chrome and Mozilla Firefox web browsers.
Click the three-lined Menu button in the toolbar
Go to “Settings.”
Go to the “Privacy & Security” section
Click the “Settings” button next to the “Autoplay” option.
From the popup, click the drop-down next to the “Default for all websites” option, and switch to “Allow audio and video.”
Go to Settings
Select Security and Privacy
Go to Site Settings
Look for Content and click Additional Content Settings
Click Sound, click the button to "Sites can play sound"