I have Sony 270ES projector, it is 4k/60hz HDR projector. I have Sony HT-ZF9 soundbar (Dolby Atmos) with rear speakers, so it is 5.1 system. And I want to have HTPC to run it. Problem here is that ...

The Apple USB-C VGA Multiport Adapter lets you mirror your Mac display to a VGA-enabled projector, TV or display in up to 1080p HD. Thankfully there are cheaper third-party USB-C to VGA adapters.