If the Joomla Quick Update Icons are missing from the Control Panel go to the Extensions Manager and click Discover. You should see the plugins listed as:
Quick Icon - Joomla! Extensions Updates Notification
Quick Icon - Joomla! Update Notification
Select the plugins with the checkboxes on left.
Click the Install button at top.
The Joomla Quick Update plugins should now be installed and appear on the Control Panel.
