A plugin is made of a number of components. Each component is a single kind of object in Dataiku DSS. If you would like to add additional components, for example, an API configuration preset, you would want to add a parameter set component. As you can see in the image below, these are separate components > "parameter set" vs. "python-connectors".
Adding a parameter set component allows you to create predefined parameters for the plugin under Settings > Parameter set.
You can view an example of this in our API connect plugin, which is for a custom dataset and has a parameter set: https://github.com/dataiku/dss-plugin-api-connect
Also, you may be interested in checking out this tutorial series: Examples of Plugin Component Development.
If you have any questions, please let us know!