AC1200 extender Netger user set up

Hi all, I hope you can help. We replaced a broken Netgear extender with the AC1200 and after set up via WPS we've been unable to create an account on www.mywifiext.net. The site makes the presumption we already set up an account (asking for username and password rather than "Create New Account"). After trying a factory reset a few times we still have the same problem. Using the current version of Chrome to do this, have cleared the cache and cookies a few times as per troubleshooting guide but nothing has worked. Does anyone have any ideas? Our goal is to create our account so we can login and change the name/password on the extender.

TIA

Lou