I do not see it there neither. So you can download and install it.
How to:
- Old style:
- Place the package at .../core/packages/
- Go to Extras, Installer
- Click on the arrow just to the right of "Download Extras" and choose "search locally for packages"
- New 2.3 style (didn't try it myself)
- Go to Extras, Installer
- Click on the arrow just to the right of "Download Extras" and choose "Upload a package"
Then you will need to apply this fix for the layout issue: https://forums.modx.com/thread/92380/google-analytics-dashboard-widget-1-0-1-pl-layout-fix-for-modx-2-3-x#dis-post-506672

Thanks for this, however my whole MODX manager is all messed up now..
The instruction quoted above from me, is a fix for Google Analytics WIDGET, not the dashboard.