Is it possible to make a Bluetooth microphone from a Linux computer?

Question

linux

I would like to run some kind of service (preferably ready-made, but if not, then roughly understand how to do it) on a Linux machine, so that this machine looks like a Bluetooth headset (or rather, like a Bluetooth microphone, only the sound source from this machine is important).
So that after pairing with this device, the phones will receive streaming audio from this Linux machine.
(The sound source itself on a Linux machine is out of scope, but if it matters, the sound will be read from the line in input)

Answer 1

It sounds like Linux is superfluous here. You need to make a sound from line-in to bluetooth, well, take some kind of transmitter, like https://ru.aliexpress.com/item/B6-2-1-Bluetooth-4-... Plug
a line into it -in, and catch blueberries where needed.
If suddenly on Linux you need to do some manipulations with sound, then the scheme is as follows:
line-in -> linux -> line_out -> bluetooth transmitter