I have put in my session creation 
“input_audio_transcription”: {
“model”: “whisper-1”,
“language”: “fr”
}
as described in https://platform.openai.com/docs/api-reference/realtime-sessions/create
But when I receive the message type": "conversation.item.created I have no user message in the "transcript field:
“content”: [
{
"type":
“input_audio”,
“transcript”: null
}