In the Projects window, right click on the Libraries folder to see these options:
Make a project that produces a library as its output required for your project, i.e., establish a dependency. For more on this, see the NetBeans Help topic:
https://netbeans.org/kb/73/java/project-setup.html#projects-dependencies.
Add an existing library file or pre-built (object) file to the project.
Open the project’s Properties window to select additional options.