Connecting Hue bulb, Smartthings Hub, and Echo Dot. Can't find new bulbs

I have an Echo Dot connected to a Smartthings Hub running one Hue bulb already. NO Hue bridge. It works fine, which from what I’ve read isn’t supposed to be possible. Don’t know how I got it to work.

I bought a couple more Hue bulbs to use in a hall fixture. I can’t get ST hub or Echo Dot to find them and pair. I feel like I’m missing something simple but can’t for the life of me figure out what it is. How can I get the ST hub to find my new bulbs like it did the first one I bought?