Artist presale?

On Ticketmaster there's a countdown to an "Artist presale" starting on the 11th (it will be the first of a few different pre-presales, like O2 Priority and so on before generale sale on the 14th). Is there any info on how to get in on that? I've read the press release and some articles but I've seen no mention of that anywhere.

PS: I'm talking about the 5th July show, of course haha