How to use Bluetooth tethering via qube that is not sys-net

As mentioned here, I’m presently no longer able to use the Internet via USB tethering using a smartphone.

I am able to connect my phone via Bluetooth to a qube that was originally setup as an audio qube using the tutorial here.

How would I go about setting up Bluetooth tethering of my phone’s Internet connection via the Bluetooth connection to the audio qube I have? Given that I cannot at the moment install packages in sys-net.

I’ve tried selecting the “Network Access Point” option in Blueman Manager that appears when I right click on my connected phone; however I see an error saying it can’t find a device with my phone’s MAC address.

The settings for the WiFi connection I am using include using a randomised MAC address. Turning that off didn’t seem to help Blueman Manager find the device.

Any guides on this topic are appreciated.