Question about routing VoiceOVer to a projector when giving presentations

Hello

I make often presentations of the voice-over use. For this pourpose I connect the iPhone using a Lightning Adapter from Apple to a projector.
Is there a way when using the hdmi-connector to route the Voice-over Audio to the hdmi screen?
It happens quite often, that this is not working.

Thanks for your Help.

Regards

Daniele19