A narrative synopsis reads like a short story, rather than touching on the details of what happens in each chapter. It doesn't focus very much on subplots, except to say that there ARE some. But it focuses heavily on the character's motivation for their actions and some of the worldbuilding (depending on your genre.) You might want to look at
some of the ones that other writers have posted in the romance room. Ignore the genre---you're looking for the details of what makes it a working synopsis.
Mostly, don't panic at this point. If you don't feel comfortable sending both, just send one with a "The narrative synopsis wasn't quite as strong as I'd hoped. I'd like to spend some more time on it, so if you still want to see it, I can send it in a week or so. But here's the chapter outline to get you started."
Or something like that. In the alternative, you can say write back to say that you're doing a final proofread and will send everything in a week or so. That's perfectly acceptable in the business.
Relax and just send your best work---whatever that might be.
