UWP create VPN connection

Currently I'm trying to figure out, how to add a VPN profile and connect to it from my universal app. I can connect to existing VPN connections with the Windows.Networking.Vpn namespace. I can also add a profile, but can not find a way to set all the required information (PSK for example). There is no documentation about this namespace in the MS docs. I also saw that there are two different profile namespaces available: VpnNativeProfile and VpnPlugInProfile. What is the difference between them? Currently I'm not at home, so I can't provide my current code, but it would be very helpful if someone can give me some hints. Is there a documentation available somewhere else?

Edit 1// Here is my sample Code

Creating a profile

VpnManagementAgent mgr = new VpnManagementAgent();

VpnNativeProfile profile = new VpnNativeProfile()
{
    AlwaysOn = false,
    NativeProtocolType = VpnNativeProtocolType.L2tp,
    ProfileName = "MyConnection",
    RememberCredentials = true,
    RequireVpnClientAppUI = true,
    RoutingPolicyType = VpnRoutingPolicyType.SplitRouting,
    TunnelAuthenticationMethod = VpnAuthenticationMethod.PresharedKey,
    UserAuthenticationMethod = VpnAuthenticationMethod.Mschapv2,
};

profile.Servers.Add("vpn.example.com");

VpnManagementErrorStatus profileStatus = await mgr.AddProfileFromObjectAsync(profile);

Connecting to the VPN

PasswordCredential credentials = new PasswordCredential
{
    UserName = "username",
    Password = "password",
};

VpnManagementErrorStatus connectStatus = await mgr.ConnectProfileWithPasswordCredentialAsync(profile, credentials);

This works, but i don't know where or how to set the PSK.