It seems that the server you are trying to send the request to, requires some form of authentication. I'm unable to help you better because of the insufficient information you have provided. I would like you to provide me with the following, so I can effectively help you.
1. Your graph file with its externalized dependencies (e.g. metadata, etc.).
2. Input files, if the graph uses any.
3. Run log where the error is visible.
4. Does the target URL require any kind of authentication?
5. Version of your CloverETL Designer.