How can I control the volume from my keyboard?

[Mity]

I have a Logitech K400 Plus that I use with my computers when I watch TV while riding my indoor exercise bike. I had been using a Chromebook and the volume buttons above the trackpad worked perfectly to control the volume without the need for the TV remote.

I recently bought a Mac Mini and when I select HDMI as the sound source, I can't use the buttons on the keyboard. I have to use the TV remote, which I don't want to do. If I select the Mini as the sound source, the sound is awful.

Anyone know how I can fix this? My TV does not have a 3.5mm port.

 

[MacCheetah3]

I recently bought a Mac Mini and when I select HDMI as the sound source, I can't use the buttons on the keyboard. I have to use the TV remote, which I don't want to do. If I select the Mini as the sound source, the sound is awful.

Anyone know how I can fix this? My TV does not have a 3.5mm port.

Unfortunately, I don’t think it’s possible.

Such a capability requires ARC/eARC:

HDMI ARC and eARC: Audio Return Channel Explained

HDMI’s ARC, or Audio Return Channel, can make your gear easier to use. Here’s how.

www.cnet.com

While the TV has support:

Use HDMI ARC or eARC with your Apple TV 4K - Apple Support

With HDMI ARC or eARC turned on, your Apple TV 4K (2nd generation and later) can receive high-quality audio from a supported TV, then play that audio through your HomePod or HomePod mini speakers.

support.apple.com

The Mac/macOS does not, as far as I am aware.