From the left navigation menu, select Content → User Generated.
Find the content pieces for which you want to add labels.
Learn how to filter content.
Once you hover the cursor on the content piece, in the upper-left corner, select the
[Checkbox].
Select
[Label dropdown menu].
Select a label from the dropdown list.
To add a new label, type the name in the search box and select
Add new label.
Select Apply.