Using blue ocean to create a pipeline with Github Enterprise option, and Github Enterprise has enable "private mode", user should leave the blue ocean UI, to define a credential.

While pipeline is creating from blue ocean ui, it doesn't allow to select credentials, and after create the pipeline, user must to go to the pipeline configuration and select a credential, if user doesn't define a credential, pipeline doesn't start on.

This last step might be avoided adding an option to select a credential from Blue Ocean UI while pipeline has been creating.