How do I make Windows 11 play the same sound through all speakers in a 5.1 system?

I have a 5.1 system that I recently bought knowing that a single 3.5mm port isn't enough to provide all six separate channels. That wasn't even my goal. I just want all 5 speakers to play the exact same audio, as I have them all lined-up in front of me. My main issue is that I'm using my monitor's 3.5mm jack, so I can't seem to find any option in the Windows sound settings to change the audio playback device to stereo or mono. I'll mostly be using it for work with VLC.

Does anyone know how I can set this up so all speakers play the same sound? These are the devices involved:

ThinkPad T480 (audio jack doesn't work)

ThinkPad Thunderbolt 3 Dock 40AC

ThinkVision P27h-10 connected through DisplayPort to the dock.

Logitech Z506 connected through a single 3.5mm cable to the monitor's headphone jack.