Comment 71 for bug 1576559

There main reason the HFP profile is not available is the Pulseaudio drivers have removed support for it. Any Bluetooth device can now only connect via A2DP configuration which does not support on-device microphone. I myself had the same problem and had spent around a week to figure out the solution that works without much hassle. You can follow the instruction mentioned at
https://eternalgeek.in/index.php/2021/06/13/solving-mic-of-wireless-earbuds-not-working-on-ubuntu-20/

Till the time the support get added back into Pulseaudio I think this might come in handy.

Hope this helps and save time at your end!