Shutter sound

When taking 'live photos' the shutter sound is off.

If you turn off the option of 'live photos', you will hear the sound.

I just checked this ;-)

If you make a portrait photo you will also hear te shutter sound.

Does this help?

Adjust the shutter volume on the iPhone camera - Apple Support

Is the 'ring/ silent' switch set to 'ring'?

By this I mean the switch above the volume knobs. If it's set to silent, you won't hear any camera sound.