[arch-general] How to run ofono as backend for a headset?

Hello, due to https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/Modu... I should get HSP/HFP support using ofono as a backend and setting headset="ofono", but it doesn't work. I've already started ofono using "systemctl restart ofono" and started/stopped pulseaudio, but it displays "HSP/HFP unavailable". Is there any documentation about how to connect a bluetooth headset using ofono? Kind regards Peter