Authorizing with Veeam ONE
To authorize with Veeam ONE software components (Veeam ONE Client and Web Client), a user must have the Allow log on locally privilege assigned.
By default, this privilege is assigned to users included in the local Administrators group. For users not included in the local Administrators group, you must assign this privilege manually. For details, see Microsoft Learn.
In the custom deployment scenario, you must assign the Allow log on locally privilege on the machines that host the Veeam ONE Server and Veeam ONE Web Services architectural components.