WN3000RPv2 won't connect

Thank you for any help you can give me. I recently bought a Netgear Orbi router to replace my old Linksys router. I have one satellite down in the basement. I get good coverage through the house for the most part. I do have one range extender in the kitchen because I have the ring doorbell and I want to be sure I get good coverage. I bought another range extender to put in my garage for the camera out there. Anyhow, I believe the range extender in the kitchen is WN3000RPv3. The one I just purchased is WN3000RPv2.I would like to add the booklet included with the new one says WN3000RPH-2ADPAS.  

My issue is first, I was/am confused why the booklet indicates one model but it isn't the same as the details on the back. Second, The Client Link LED never lights. Even if I have it plugged into ethernet. I have tried to power cycle it and reset it. The power light is green. So as I looked at the model details online, it leads me to believe that the model indicated on the book is for ADP use. However, based on the model on the back, I wouldn't think that is the case.

So, here I am wondering why the client link LED light never lights up. And what this extender really is for - normal range extending or ADP use only.

Also, I have seen both sides - you can only have one extender on your network. But I have also seen people indicating they have mutlitple.

Finally, I can't register this extender, the Netgear site keeps telling me it is not recognized...

Any help would be greatly appreciated.

Thank you!