Is there a public repo for the Admin plugin, I’d be keen assist if you’re accepting help.
For a moment in closed testing, when is open to all the dev staff post in the blog, no worries about it 
Our admin plugin is currently in a private BitBucket repo. We are letting select people join our private beta team, but this is more to help with continued development of the admin rather than testing as its not really in a testable state yet. If you are interested in this Shayne, chat with me on Gitter: https://gitter.im/getgrav/grav