To authorize with Veeam ONE software components (Veeam ONE Monitor and Reporter), 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 this Microsoft TechNet article.
In the advanced deployment scenario, you must assign the Allow log on locally privilege on the machines that host the Veeam ONE Server and Veeam ONE Web UI architectural components.