vpn notification

Hello,

Using a fortigate vpn with forticlient 6.0.6, which is paired with duo 2fa.

Works well with push notice received on the mobile duo app. 

Is it possible that the 2fa code be typed in (as seen in the app) instead of being approved by push.

To get this working(2fa being typed in), what configuration will be required on the fortigate for the forticlient to allow this pop-up where the 2fa can be keyed in.

Thanks.