In summary, your first headset mic did not work so you bought a new bluetooth headset and its mic also does not work. Is this understanding correct?
What type and connection was your first headset, wired 3.5mm or USB, or was that also bluetooth?
You could have a play with alsamixer, as per my suggestion here: Zorin OS 16.1 doesn't recognize my microphone - #2 by zabadabadoo
EDIT:
Also from websearch of "Realtek ALC269VC no mic Ubuntu 20.04", I found this
Note you can substitute "Ubuntu 20.04" in place of "Zorin" in websearches to get more answers.