SSO and jsConnect

I have Vanilla Forums enabled, using the enbedded version. This means that I am using the Vanilla Single Sign-on Integration plugin. The site is being redirected from linker-wenzel/forum to linker-wenzel.de/community.

Plugin and WordPress are both latest versions.

I copied all data from the “Security Settings for Single Sign-on” into jsConnect settings according to the guides I found (including the 2013 youtube video). The jsConnect Test is showing: “The SSO test was successful” and I can see all that stuff like: “The user is signed in”, “Known User Fields”, “Token Details”.

However here are the error messages:
1.) One or more of your connections has warnings. Edit a connection with warnings to get more information.
2.) Your sign in URL does not specify a {target}. You have to specify a redirect variable or else your SSO may not work.

My assumption is, that the signin URL is just wrong:
https://www.linker-wenzel.de/wp-login.php?redirect_to={Target}

What is the correct setting for {Target}? I know that this need to be tweaked but this goes beyond my skills…..

The page I need help with: [log in to see the link]