curl --request POST \
  --url https://app.yampi.ai/api/v1/accounts/{account_id}/presigned_contracts/{id}/document \
  --header 'Content-Type: multipart/form-data' \
  --header 'api_access_token: <api-key>' \
  --form 'contract={
  "file": "<string>"
}'

const form = new FormData();
form.append('contract', '{
  "file": "<string>"
}');

const options = {method: 'POST', headers: {api_access_token: '<api-key>'}};

options.body = form;

fetch('https://app.yampi.ai/api/v1/accounts/{account_id}/presigned_contracts/{id}/document', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://app.yampi.ai/api/v1/accounts/{account_id}/presigned_contracts/{id}/document"

payload = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"contract\"\r\n\r\n{\r\n  \"file\": \"<string>\"\r\n}\r\n-----011000010111000001101001--"
headers = {"api_access_token": "<api-key>"}

response = requests.post(url, data=payload, headers=headers)

print(response.text)

{}

{
  "description": "<string>",
  "errors": [
    {
      "field": "<string>",
      "message": "<string>",
      "code": "<string>"
    }
  ]
}

{}

{}