Custom Ionic.Auth.login redirects in App

I have the problem, that when i try to authenticate the user with
Ionic.Auth.login(‘custom’, authOptions, data).then(success,fail); )
There is a redirect in the App…

cordova-plugin-inappbrowser 1.2.1 “InAppBrowser”
─ ionic-platform-web-client#0.7.1

in my php backend
header("Location: ".$url);
any idea?

Well i just had a problem in the redirect url.

but it is annoying that the white browser window is popping up.