Queuing Music to Headless Plex Client

I’m interested in being able to browse my Plex managed music library from an iPad or iPhone, and then being able to select songs and have them queued for play on some sort of client device that’s connected to my whole house audio system. Ideally I’d like to use a raspberry pi or similar headless device as the actual player that’s connected to my whole house audio system.

The main goal is to be able to find and queue music from a wireless device on my patio without having to sit in front of a computer or TV that’s physically attached to the whole house audio system.

I’ve seen posts that suggest something like this might be possible, but I’ve only seen enough detail to know where to get started. Can any provide me with suggestions if something like this is possible?

Thanks!