Currently, the SOAP Webservice connector supports OAuth 2 Password Credentials Type in Design Time. However, there are instances where you need to authorize to an HTTP GET endpoint to get the WSDL definition. The workaround for this issue is to currebntly put the WSDL file on the server so authentication is not required to generate the connector. But it would be ideal to apply the current OAuth2 Password Credential Authorization to the WSDL retrieval GET operation.