Please open CamScanner app and tap the button on top left of the "Doc" page-->tap "Tag"-->"Edit" (on top right). Or please open CamScanner app--bottom "Me"--"Document Settings"--"Manage Tags"

Rename a tag: tap the tag title directly

Delete a tag: tap the red "delete" button beside the tag-->tap "Delete"

Move a tag: long press the grey icon beside the tag to move it

After tags have been edited, tap "Done" on top right to save the changes.