How to connect piwik via mobile?


I am trying to connect my piwik from my mobile(android), I typed the ‘piwik access url’ like
with username and password. but after a authentication warning, a error popped out, said ‘error - Please verify settings’.

Is there anyone can tell me how can it access the piwik from my mobile?
Do I have to enable some settings in piwik and where to do it?

Thanks very much

Jason Huang.