Cisco Webex connections are standard XMPP connections. To set up a new connection, go to the accounts tab and select XMPP connection.
Here you need to enter your Jabber ID. This is the Webex login this would be in the form email@example.com. Enter your password and then enable the account. Return to the accounts screen and it should auto connect.
You do not ordinarily need to adjust any other settings.
The resource setting does not matter and the port setting and server settings should be left alone.