How do I add the virtual instrument nki that I originally had to Kontakt 8?

I'm a little confused by your reply. You can only install and activate the libraries with Native Access, there's no way around it.

Ok, now I understand. So now for NI products you need to install them and activate them with Native Access.

Please read this: Using Native Access

In your screenshot we don't see the "library" where all the products should show, please check this part:

How does Alicai Keys show here?

What's your operating system? You're on Mac it seems but what's the OS?

Do Kontakt, Native Access have full disk access, yes or no, if not please do do.

I've quickly checked your account and there is no trace of older products that could include Alicia's Keys. You probably have another NI account attached to another email address.

So when you installed this library with Kontakt 5, I imagine a few years ago, did you do it with another NI account with another email address? This is most probably the issue here, please check in your other email accounts traces of your older NI serials and orders, once you found that, my colleagues can easily merge your accounts. Again, as I said there is no trace of Alicia Keys or other older products, only Kontakt 8 and Komplete Start the free product bundle that comes with any NI account. I see that you are already in contact with my colleagues in support. Please continue there as it requires private data.