Desperately finding a solution to delete rows in Collections

I have deleted } as well. red dot disappeared. Thank you. Still items not deleted.
Can you kindly look at the image below and tell me where exactly i need to paste the code:
I thought to start from the beginning.

So, I have a collection called Dresses, and have created a Dynamic page - Dresses
Then I created a another page under menu called Dresses

I created a new page
Added a dataset, connected to Dresses collection. Which is the image you see below.