Use Veeam Agent for Microsoft Windows to backup to Veeam Backup & Replication Community Edition.
Need to be on the same local network or VPN as the server.
You can either create a backup job in the agent directly, or let the server manage it.
To allow the Veeam agent to be managed by the Veeam Backup & Replication server you need to create a policy to override the default security policy that disables access to administrative shares:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system