ProcessMaker zimlet Error : Login to ProcessMaker failed!

Hi Community,

I am new in Zimbra and we need to try the ProcessMaker zimlet in our ZCS infrastructure. After uploading the ProcessMaker zimlet we encounter an error:

Login to ProcessMaker failed!

-Connection Error-

Check your internet connection and Review your preferences.

I have read some links and resolution like this link:

But I don't know where I can find the

" no restrictions connecting to external servers (by default it always restrict)"

in the default COS or the ExternalDefaultCOS

Please let me know the exact part of the application where I can enable it.

Any help would be appreciated.

Richard Catibog