Oh, okay, not sure this will be the only issue but you'll need these credentials to be valid, since they are used by the ClearML Agent to connect to the ClearML Server 🙂
The easiest way to generate credentials is to open the ClearML UI in the browser, login with an Admin user, then navigate to the Settings located on the top right corner when clicking on the user icon. From there go to "Workspace" and click "Create new credentials" and use the value provided