As of Opus 2 7.4, the TIMELINE (Beta) option can now be turned on within your Chronology. It will need to be enabled in the Admin tab by a user with Workspace Administrator rights.
The Timeline option needs to be enabled on a per-workspace level, in the Workspace Admin tab > Settings section:
Remember to click on “Save Changes” once the selection has been made, and also to refresh the Chronology tab if it is already open on your browser so that the changes can be applied. Once enabled, the Timeline button will be available in the Chronology tab toolbar.