This endpoint receives an object with the MFA parameter name (aka 'token') as key. This name is obtained from parameter field in an item in USER_WAITING_INPUT status. The following is an example of an item in that status:

{
    "id": "a9481a68-38cc-4433-bfcc-dafc05022c60",
    "status": "WAITING_USER_INPUT",
    "executionStatus": "WAITING_USER_INPUT",
    "lastUpdatedAt": null,
    "error": null,
    "parameter": {
        "name": "token",
        "label": "Chave de segurança",
        "type": "string",
        "placeholder": "Exemplo: 123456",
        "validationMessage": "O token deve ter 6 números.",
        "expiresAt": "2022-12-14T19:09:08.780Z"
    }
}

This parameter field is an object with all MFA parameter information, included name. The value of name field is what you should use in send MFA request body as following:

{
  "token": "123456"
}