Using ADSelfService Plus GINA agent with Windows Native VPN to change cached credentials

Using ADSelfService Plus GINA agent with Windows Native VPN to change cached credentials

When enabling the VPN settings for updating the cached credentials via GINA, I wish to use the native Windows 10 VPN Client. The ADSelfService configuration requests a Pre shared Key for this type config, and the instructions are not specific. Do I need to configure an endpoint on the Win 2012R2 RRAS VPN server with the same pre-shared key? 

How do I troubleshoot issues with this feature (logs)? 

Thanks!

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