The Audio block is not working on iOS devices.
I gave up trying to make it appear so I uploaded my sounds to a 3rd party host so I could embed the files via . The problem was the button was not clickable, It seems like there is an offset of about a few cm above it. You need to find that offset for you to be able to play the sound. It is very frustrating.
PS: It seems to be working on Desktops, and Android
I paid for the plugin thinking it would solve the problem, but it was not the case.
It is bug in Safari https://bugs.webkit.org/show_bug.cgi?id=278898 , we will publish a fix in 1.16.2.
Update the plugin.