curl --request POST 'https://api.voicecheap.ai/v1/actions/projects_upload_sign_parts' \
  --header "x-api-key: $VOICECHEAP_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{"uploadId":"a1b2c3d4-e5f6-4789-8abc-def012345678","partNumbers":[1],"requestId":"13579bdf-2468-4ace-8bdf-0123456789ab"}'

const input = {
  uploadId: 'a1b2c3d4-e5f6-4789-8abc-def012345678',
  partNumbers: [1],
  requestId: '13579bdf-2468-4ace-8bdf-0123456789ab',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/projects_upload_sign_parts', {
  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/projects_upload_sign_parts",
    headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
    json={"uploadId": "a1b2c3d4-e5f6-4789-8abc-def012345678", "partNumbers": [1], "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"},
    timeout=120,
)
body = response.json()
if not response.ok:
    raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)

{
  "data": {
    "presignedUrls": [
      {
        "partNumber": 1,
        "url": "https://media.example.com/upload-part-1"
      }
    ]
  },
  "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"
}

{
  "data": {
    "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab",
    "operation": "projects_upload_sign_parts",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "running",
    "pollAfterSeconds": 5
  },
  "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"
}

{
  "data": {
    "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab",
    "operation": "projects_upload_sign_parts",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "completed",
    "resultStored": false,
    "message": "The action completed. Retrieve its output from the corresponding history or resource action."
  },
  "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"
}