If you’ve accidentally deleted the App Drawer icon from the dock area, this is how you get it back :
1- On a home screen, long tap to see the Add to Home screen menu, and then select Nova Actions.
2- Select App Drawer, and the icon will be created automatically.
Now, long tap and drag the App Drawer icon to the dock area.
Note: Besides the App Drawer, you can use the same steps for other items in the Nova Actionsto add them to the dock area.