When dialing in to my Google voice number GV is asking for a pin

[Woody]

When dialing in to my Google voice number GV is asking for a pin and not just dialing the number.

[RonR]

You don't dial into your Google Voice number to make a call.  You simply dial the desired number and the OBi uses Google Voice as the provider to establish the call.

[jimates]

When dialing in to my Google voice number GV is asking for a pin and not just dialing the number.

If you are calling your goggle voice number from one of the phones in your forwarding phones list, it is likely set for direct access to voicemail. With direct access to voicemail it will always ask for a pin because it thinks you are calling to check your VM.

turn off direct access if you want to call your google voice from that phone.
in the phones list
edit > show advanced settings > voicemail access = NO

With direct access set to NO, you will have to press * when the ringing starts to access the GV IVR.