Hi,
>there is no way to set the pre-shared key, so using a lt2p w/ pre-shared key is not possible. Any possibility for a update to allow setting the pre-shared key?
It seems that there is no way to set PSK with the code in UWP.
https://stackoverflow.com/questions/47280840/uwp-create-vpn-connection
This is a C# UWP VPN sample.
https://github.com/bsld/Csharp-UWP-VPN-Sample
Also please note that Microsoft does not encourage the use of preshared keys, because it is a less secure method of authentication than certificates. Preshared keys are not meant to replace the use of certificates; instead, preshared keys are another method for testing and internal operations. Microsoft strongly recommends that you use certificates with L2TP whenever possible.
https://learn.microsoft.com/en-us/troubleshoot/windows-server/windows-security/configure-preshared-key-to-use-l2tp