no chat area anywhere, with SSO CAS

Hello,

We use CAS SSO in our Zimbra infrastructure :
CAS | Jasig Community

And chat area does not open.

The debug mode allows us to determine the cause:
"delegated_or_resources_not_allowed"

I can pass the JSP used for authentication (zimbraWebClientLoginURL)

An extract:
...
DelegateAuthResponse dar = null;
try {
dar = sp.delegateAuth(AccountBy.name, userAccount.getName() , ZCS_TOKEN_LIFETIME);
}
...

Will it have a solution?