curl --request POST 'https://api.voicecheap.ai/v1/actions/tts_download' \
  --header "x-api-key: $VOICECHEAP_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{"historyId":"722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d"}'

const input = {
  historyId: '722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/tts_download', {
  method: 'POST',
  headers: {
    'x-api-key': process.env.VOICECHEAP_API_KEY,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify(input),
});
const body = await response.json();
if (!response.ok) throw new Error(body.code + ': ' + body.message);
console.log(body);

import os
import requests

response = requests.post(
    "https://api.voicecheap.ai/v1/actions/tts_download",
    headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
    json={"historyId": "722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d"},
    timeout=120,
)
body = response.json()
if not response.ok:
    raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)

{
  "data": {
    "downloadUrl": "https://files.example.com/launch-script-speech.mp3"
  }
}