connecting Asus rtn66u to fibre

[#1]

Hi
I'm trying to connect the new Asus router to my fibre connection to plusnet fibre. When trying to set up the router it is asking for account name and password. I put in  the SSID and Key but it is coming back as incorrect. Any ideas of what I need to put in.
Thanks in advance

[#2]

The SSID and key are for wireless access. To set up the Internet connection(that's what I assume you want to do) you use your plusnet account details, <username>@plusdsl.net and the password. It's the same as the one you use to access the member centre

[#3]

do you mean the pop up box?
if so its admin/admin
when you set up your security key password
it becomes admin/security key password

[#4]

No not admin/admin. That just gets you into the router interface.
Use the quick setup routine to connect to PN using the info above. It takes you through the setup step by step starting with the PN connection then once that is complete the wifi setup.