Hi Oleskii, thanks for the question! You can give this a try…

POST https://api.getguru.com/api/v1/folders/{parentFolderId}/action

Request Body:

{
  "actionType": "add",
  "folderEntries": "
    {
      "description": null,
      "entryType": "folder",
      "title": "folder name here"
    }
  ],
  "prevSiblingItemId": "first"
}

Setting the prevSiblingItemId field to "first" will position the folder at the very top of all other subfolders. If you'd like the folder to appear after a specific folder instead of at the top, enter the ID of the folder you want it to follow.