Custom ElevenLabs voice not working for agents

I added a custom voice for elevenlabs together with my request to create an agent by adding

"x-api-key-external": "myElevenLabsKey"

to the request and the voice in the presenter

 "presenter": {
        "type": "talk",
        "voice": {
            "type": "elevenlabs",
            "voice_id": "0d7PmtkKJbIWQv5PVYJW"
        },
        "source_url": "https://test.com/output_image.png",
        "thumbnail": "https://test.com/output_image.png"
},

And it doesn't work. The agent just never speaks.