If you need to update Acronis Agents on a large number of machines, use the web interface and Agent auto-update feature.
Auto-update feature is implemented starting from version C21.05 (Agent build 15.0.26986) - see details in https://www.acronis.com/en-us/support/documentation/CyberProtectionService/#updating-agents-automatically.html
Automatic updates are available for agents version 15.0.26986 (released in May 2021) or later. Older agents must be updated manually to the latest version, first.
The update time is not specified. If you have the auto-update enabled the update is queued and it can take several days to be run.
The maintenance window for installation and other options can be configured in Edit default agent update settings:
In case using Agent Auto-update feature is not an option for some reason, please contact Acronis support to receive a mass update script and instructions for using it.