How do I connect my HomePod mini to my iMac?

I bought this thing about a year ago to use as a Bluetooth external speaker with my iMac. It sounds pretty good but the user experience is very frustrating. It frequently won't play. Usually I can get it going (somehow, not usually clear what the problem is or how I get it working again. I have kept up with the firmware updates and all the Software Updates. Had hoped one of those might help but not really. Last week I could not get it going no matter what I tried. This led to my query above. Tried unplugging it, reset from the Home App. After reading here, for the first time I tried "remove". It looked a little different (new name?) after reinstall so I was initially hopeful but could not get sound from my iMac to the device. The sound would stop on the iMac but not play on the HomePod. Gave up and went to bed. In the morning it was working as if nothing ever happened. Very frustrating gadget, not like most of my Apple experiences over the last ~35 years. Hmm, I guess there have been a few but...