When you are in "start a new hub" and you are the page where you will write your hub. Look at the upper right corner you will see "add more capsules, click on Amazon. It will load it at the bottom of the page of your hub. You can put specific items from Amazon, which you will have open in another tab on your computer. Or you can put in specific words and Amazon will pick for you. Remember you can move a capsule, add more or remove them.
Hope this helps. They do not show up automatically on your hub. You control it.