iCloud sync allows to periodicly sync activities between multiple devices. An active iCloud account with iCloud Drive enabled is required on your device for iCloud sync to work. Counfigure iCloud Drive in your macOS system preferences.
Setting iCloud support in TimeKeeper
Enable `iCloud Drive` support in macOS, go to `System Preferences` and check `iCloud` section
Open `Preferences` in TimeKeeper and select `Sync` tab
Choose `iCloud` in `Sync activities to` preference