How to add Integra DRX-3.4 receiver to Apple Home?

I just purchased an Integra DRX-3.4 receiver. It is airplay capable. I want to be able to control it using Siri through my Homepod hub, e.g., "Siri, play all songs shuffled on Integra." How do I add the receiver to Home such that it's another device? I don't have a QR code for it and holding my phone near it, even though it is on my wireless network, does nothing. (I can stream sonsg to it using my iPhone, but I want to be able to control it using a command to Siri via Homepod hub.) Thank you!