How to view and read cached page

Question

I am wondering if there is a way to view a cached page from my insurance benefits. Long story short, they are telling me that my kids were never on the plan, I am certain they were. I viewed my benefits last month which showed them enrolled. Of course now I cannot see that. Wondering if there is a way to access the old copy of the page to prove it?

I have tried the chrome://cache/ and can see lots of cached info but don't know what to do with it or how to read it.

The site does require a username and password. Not sure if that matters.

Thanks!