Configuring Liferay Service Plugin-Collection of common programming errors

I have created a liferay service using the Service Builder framework. This service is used to fetch content from an external source, and once it is deployed, it is available to all portlets.

Is there a way to add configurations to plugins of this type ? In normal portlets, you can add a configurations page, which allows you to change the portlet’s preferences in runtime. In this type of plugin, there is only one instance, and it is not meant to be dragged to pages like normal portlets so how would one add configurations to such plugin ?

Any help would be much appreciated. Regards