Jenkins Pipeline : How to access plugin contributed Global Configuration values

I'm working on a Jenkins Pipeline script and ran into a case where I need to get a value that is set in the Jenkins Global Configuration. The Manage Jenkins : Configure System page is where I set a value for one of the plugins installed. The plugin provides a configuration line to add a URL (Confluence URL). I want to access the URL in my pipeline to use for a specialize step. The issue I'm having is I'm unsure how to get a global configuration defined by a plugin. Is there a way to access global configuration values from a pipeline? Or would the plugin have to expose it?