RN214 Veeam

I cannot locate anything that passes for actual documentation on the Veeam site that walks you through a set-up that you can get without signing up for an account.  But it is asking for a shared folder, not a server.  So, are you putting in the name of a share, or just the NAS name/IP.  From the description you give, I suspect you need to put in the name of a share.  What the format is for that, and how you manage the credentials for access, I don't know, but I wouild guess \\IP.of.the.NAS\ShareName for the input format.  I recommend you stick with the IP address and insure it's always the same by reserving it in your router.  My experience is that Windows sometimes has difficulty finding the NAS by name, and I have been unable to figure out why.  Alternately, you can put the NAS name in the Windows HOSTS file, but that still requires a fixed IP address, so it's just a convenience thing so you don't have to remember the IP address.

You have hit the config for the Veeam Backup Repository destination, not the Shared Folder one....