WebEx Meeting BCR für Citrixumgebung

[mapa1]

Hi there,
since our firewall doesn't allow UDP for the "Webex VDI" app, I wanted to use browser redirection (BCR) (Webex webapp). This works e.g. for Youtube.

I can't find any settings for Webex.
The following pages are registered in the BCR - ACL guidelines:
https://idbroker.webex.com/*
https://idbroker-eu.webex.com/*
https://idbroker-static.webex.com/*
https://signin.webex.com/*
https://staatskanzlei-lsa.webex.com/*
https://akamaicdn.webex.com/*
https://cdn.appdynamics.com/*
https://cdn.digitaladopt.webex.com/*
https://col.eum-appdynamics.com/*

However, this leads to the following error after logging in:
"Missing attributes."

How can I use the Webex Meeting website for BCR?

Best regards
Mario