curl --request POST \
  --url https://api.useanima.sh/v1/voice/calls \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "to": "<string>",
  "agentId": "<string>",
  "tier": "basic",
  "greeting": "<string>",
  "fromNumber": "<string>",
  "systemPrompt": "<string>"
}
'

{
  "callId": "<string>",
  "state": "<string>",
  "from": "<string>",
  "to": "<string>",
  "direction": "<unknown>"
}