Sound doesn't work on iPhone

Hello !
I have an audio file for background music, it works fine in the PC browser, but on my iPhone it doesn't work. Have you come across a situation like this? Can you give me the solution? Thanks.
This is my code:

<plugin name="soundinterface" keep="true" url="plugins/soundinterface.js" preload="true" volume="1" mute="false"/>

<action name="startup" autorun="onstart">
playsound(bgsound, audio/bgsound.mp3, true, 0.75);
</action>

Hi Klaus !
I tried to click / touch but it doesn't work.

Hi Klaus !
I tried to click / touch but it doesn't work.
UPDATE:
It works but only with headphones, when I am not using the headset no sound is played at all.
I tried on:
ipad IOS 11 (work),
iphone 6 iOS 12 (not working),
iphone 7 plus IOS 13.5 (not working),
iphone 7 plus IOS 14.2 (not working),
iPhone XS Max IOS 14.2 ( work)

Quote from klaus.krpano

Hi,

playing a media without user-gesture (click/touch) is not allowed (by the browser).

But that means: after touching anywhere on the screen, the sound should start automatically playing (assuming you're using an actual krpano version).

Best regards,
Klaus

Quote from klaus.krpano

Hmm... that doesn't make much sense...
The iPhones are not muted or have volume set to zero?

I'm not sure about this, but when I tested it on a few Apple devices, it did.