Make sure everything is in caps and pay attention to O and zeros.
If that doesn't work can you connect an Ethernet cable to your NOW Router with something like a laptop and type 192.168.0.1 in your internet browser url address bar.
Then when the NOW Hub Settings web page appears on your screen, click on the wireless tab and when prompted use admin and nowtv has the username and password then go to the Network key box and use a wifi password of your choice, then click on the green Apply button to save.
Forget to say double check if the sticker on the NOW Hub Router box packing and the sticker ID underneath the bottom of the NOW Router has the same information.
Also you could try pressing the WPS button on the front of the NOW Hub.
You should find your password on the underside of the router.
All your WiFi devices will need to be individually reconfigured to use the SSID and password of the new router*.
Or are you saying you are doing that, but the password shown on the router is not accepted by the router? In which case, carefully reread the password, and ensure you are using the correct case for each letter, as passwords are case-sensitive, and that you aren’t confusing numeral 0 and upper case O; lower case l, upper case I, numeral 1; and so on.
In the unlikely, but possible, case where the label on the router is wrong, then if you have a device that can connect to the router by WPS, do this, and then browse to the router and see what the password really is.
*Or get one device, with a browser on it, connected, and then change the router SSID and password to whatever you had on the previous setup, after which all your existing devices will automatically reconnect. Much easier to change one router than 20 devices 😛