As @Christoph_Souris notes, you can select additional keys to view via the Show and hide keys.
That said, you likely don’t need to configure this at the server level. Instead, configure CORS for the API of interest using the Response Processing policy. In that you can specify the allowed origins, headers, credentials and methods.
A note of caution – the way one specifies the list of allowed headers, etc. in the policy differs from how it is specified in the server level config. For server level config it accepts a comma-delimited list. The policy needs to have each entry on its own – click the Add button multiple times, don’t enter a delimited list.
#API-Portal#API-Gateway#webMethods#API-Management