If you need to update direct via back-end, you should purchase your license key. At the moment, you are using WarpTheme license (Quix Extended license). Please ask the update question for Quix via ticket system https://warptheme.com/member-area/ticket-system/ We will provide the update package for you.
NOTE: Quix 2.0 itself not really stable, missing front-end elements so you should wait for stable release.
Thanks
