curl --request POST \
  --url https://app.kapso.ai/api/v1/voice_agents/{voice_agent_id}/voice_agent_whatsapp_configs \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '{
  "voice_agent_whatsapp_config": {
    "whatsapp_config_id": "config-123abc",
    "is_primary": true,
    "enabled": true
  }
}'

{
  "data": {
    "id": "vawc-123abc",
    "voice_agent_id": "voice-agent-456def",
    "is_primary": true,
    "enabled": true,
    "whatsapp_config": {
      "id": "config-123abc",
      "name": "Client WhatsApp",
      "display_name": "Client WhatsApp (+1234567890)",
      "phone_number_id": "1234567890",
      "business_account_id": "98765432109",
      "webhook_verify_token": "<string>",
      "webhook_destination_url": "<string>",
      "customer_id": "customer-456def",
      "created_at": "2023-11-07T05:31:56Z",
      "updated_at": "2023-11-07T05:31:56Z"
    },
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z"
  }
}