How to obtain my WRMU DEV API key?

I purchased a copy of MarketPress.
I was asked to install the wpmudev dashboard plugin which I did, and activated.
I now see a screen asking me to obtain my api key. There is a small link saying 'Already a member? Click here' but this links to '#' i.e. nowhere. No username, email, password combination I can think of allows me to progress beyond this screen. Help.