But it is in german. No big deal , easy enough to navigate. 

And, you have to use the configurator tool thing which generates 2 config files, one of which you import as a new vpn profile into the fritzbox, and another which you import into the windows 10 vpn client.    

I couldn't easily make it work with my existing fritzbox vpn profile as the fritzbox does not give you much control over existing vpn profiles. 

Fortunately, importing a new vpn profile should not affect the existing vpn profiles in the fritzbox, just use some other email address when the configurator asks for an email.

And, one more bad thing, I couldn't get my netbios name resolution to work (works with the shrewsoft client though), so have to use your lan ip addresses to access local resources. Unless someone figures this out for me :)