Cant use audio from background

[kisso]

Hello, I am trying to connect to call from background, I get VoIP notification and after accepting the call I start app and get following error:
CALL_ANSWERED
stream: update 'audio'
audio: Set audio decoder: PCMU 8000Hz 1ch
�[31maudiounit: AudioSessionSetActive: 1701737535
�[;m�[31maudio: start_player failed (audiounit.default): Operation not supported
�[;m�[31mcall: update: audio_decoder_set error: Operation not supported
�[;maudio: Set audio encoder: PCMU 8000Hz 1ch
�[31maudiounit: AudioSessionSetActive: 1701737535
�[;m�[31maudio: start_player failed (audiounit.default): Operation not supported
�[;m�[31maudiounit: AudioSessionSetActive: 1701737535
�[;m�[31maudio: start_source failed (audiounit.default): Operation not supported
�[;msip:*8@sip.example.sk: session closed: Operation not supported
CALL_CLOSED

When I am doing same from foreground it works.

[Koshub]

@kisso
Did you enable background audio & Voice over IP modes in your XCode project?