API Manager Catalog "Try it Out" feature - TypeError: Failed to Fetch

Has anyone else seen this error?  From the API Manager Catalog, I can select an API and use the "Try it Out" feature.  An error is returned - TypeError: Failed to fetch.

The same Curl can be imported into Postman and executed successfully.  For us, API Manager is in a container and the container can ping the server. Also, this error is in the Developer Tools/Console -

Access to fetch at <request removed> from origin <host:port removed> has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
 

Does anyone have suggestions?  Thanks in advance!