FTP credentials are a username and password that allow someone to log in to the server and download the files that create the website.
This method of storage is not used by Rocketspark as there are security risks when it comes to FTP. Rocketspark has a more secure way of holding the website data. Unfortunately, there is no way to log in and get the website data.
This means that it is not possible to log in to the server and get the website data.
If you have any questions at all, please contact support@rocketspark.com.