Update: Maybe i was beeing stupid or had a bad connection - but now it worked…
Thanks to ompamo 
mhh… i am kind of stuck. I have 2 users + pass through s***, but wanted to try the x**. It works on my local box, but not on redcross. Maybe because on the other side there is no user with browser, but a curl script? Tried different aproches, but maybe i fail because its my first x** 
If somebody want to help / discuss please pm.