There is no credentials page to login. It's a one-time password. Once connected you don't need to do the password again after rejoining the campground wifi.
After a 1 hour 3 minute call with Netgear tech support I was told that the EX6120 will not work with this wifi because of the credentials (filters) that the campground has set.
I need to order a mesh type extender. That would be a Netgear EX6100 V.2.
I thought I had done my homework but, I guess not!