Hello,
I'm sorry you are having issues with the configuration for this device.
First of all I would like to mention that this device was not designed to work or be compatible with google voice so I'm not sure if it will work (My guess is that it won't).
Now, regardless of the service you are using, there are a minimum of configurations that will need to be entered to be able to register the device to make calls.
You will need the proxy name or domain name for the service, usually something like Sip.Provider .com.
Then you will need The display name, which is usually same as the user id, normally it will be the phone number assigned to your account
Lastly you will need the password.
Go ahead and try entering this info if you have it, but even if you do I dont expect for this to work as the device is not meant to be compatible with Google Voice.
Please let us know.