In this instance, you could use the VBK Extract Utility (https://helpcenter.veeam.com/docs/backu ... tml?ver=95
) and use that to open the VBK file and extract your Veeam Server, then upload it into a datastore, register the VM, and power it on. A good tip is to grab a copy of the Extract Utility out of the Veeam Backup folder and place a copy (or a couple of copies) in separate locations so you have access to it in a disaster.
I'd suggest protecting the Veeam Server in its own backup job to keep that VBK file as small as possible so there is less for the extract utility to process.
You could also use Veeam to protect itself with by creating a replica of itself, with a Veeam Replication Job, onto another ESXi server and storage system.