LeadPages plugin not working

I have installed LeadPages plugin on my site. The Leadbox part of the plugin works but I can't create a LeadPage format on my site. e.g. I'm trying to create a page that looks like https://lizcopeland.leadpages.net/landingalt/ but is a page created by the plugin within Wordpress and should be at http://lizcopeland.co.uk/minisite4. If you try this URL it generates a 404 error. The site is up to date (Wordpress, theme, plugins) and I've disabled all plugins except LeadPages and still no luck. It may be a glitch between Wordpress and the plugin but just in case it is theme related I thought I'd post this problem here. the regular site URL is http://lizcopeland.co.uk