Hi tonytheblue,
There are two addresses that you'd be able to use to access the router settings, each one dependent on the mode your Hub is in at that time.
You would enter 192.168.100.1 into the address bar if you're in Modem Mode, but if you're in Router Mode then you'd enter 192.168.0.1 into the address bar, as we also detail here.
We can see that you've mentioned that the Modem Mode number when entered does not work for you unfortunately, but there's been no mention of the Router Mode number being attempted whilst in Router Mode. As such, can you please try to access it via Router Mode and with the number above for Router Mode and let us know how you get on?
Thanks,