Invisalign bite ramps? Are they for attachments? (Photo)

Hi, so I have invisalign. And my ortho gave me a set of 10 trays until my next appointment. Anyway, I had no issues until recently. I had to switch aligners, and my next set look so different. Basically, there are bumps on the BACK of the front teeth of the trays. I went online and I guess they are called bite ramps. My question is: Am I supposed to get attachments on the back of my teeth now? For the bite ramps?