Please redirect category "Dungeon Item" to category "Dungeon Items".

So, I created a category named "Dungeon Item", but there is a more popular category called "Dungeon Items". I tried to redirect my page to that page but it's not working. When I refresh the page it just has a red link that when I click on it, says I need to create the category, even though it already exists. Somebody please redirect my category to that category.