Log on to the Veeam UI as a user who is a member of the Veeam Virtualization Extensions Users local group. The Veeam UI will open at the Dashboard tab. It can be seen that there are 3 (currently Inactive) Veeam Collectors available.
When a more advanced configuration featuring multiple Collectors and monitoring groups is required, it is strongly advised to first configure the groups and Collector assignments before adding vCenter Server connection(s). Click the Veeam Collectors tab to proceed.