Do I have to transfer my domain to Prolateral to use the Secondary DNS or Backup DNS?
No, you do not have to transfer your domain to Prolateral to use the Secondary DNS (Backup DNS) service.
To use the Secondary DNS (Backup DNS) service you need enter a valid source server IP Address and also ensure that server has been given permission to allow zone transfer to the following servers
If you want the DNS-Engine name servers to answer DNS queries you will need to add them as NS servers in your domain information.
If you want the DNS-Engine name servers to purely act as a backup service and not answer domain name queries then you can omit these servers from the NS information.