Headphone issue

Hi, I'm trying to use a iMac (Retina 5K, 27-inch, 2019) that is located in a library at my college campus. When I try to connect a pair of PrimeAudio Headphones via bluetooth, they are able to connect properly, but they don't show up as my audio output. Since this is not a computer that I have administrator access to, I can't update macOS 12.0.1 to the latest version.

I just tried connecting my headphones via bluetooth to my MacBook Pro (2019 16") running macOS 10.15.7, and I had no issues whatsoever with the device being used as an output device, so, that means it's an issue in macOS 12.0.1.

The only way I've been able to work around the issue is to bring in a separate pair of wired headphones every time I plan to use these imac computers at school. Most pairs of wireless headphones come with the ability to work with devices that don't have a bluetooth connection, but, since I purchased these headphones from five below for $5.95 (plus tax), I'm only able to connect them via bluetooth.

I'm not convinced these headphones sound very good when used with a computer. The sound quality is terrible. When I use them with my iPhone, they sound good enough.

Is there any other way I can make these "prime audio" headphones work? thanks