Public signup for this instance is disabled. Go to our Self serve sign up page to request an account.
See discussion here https://lists.apache.org/thread.html/r5f1637cb70c9ea1294789be6e1e408abc576803544437f46b561a745%40%3Cdev.zeppelin.apache.org%3E
And the design doc
https://docs.google.com/document/d/1bLLKKxleZlZpP9EFJlLLkJKwDBps-RNvzNwh3LFZWZ4/edit?usp=sharing