It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
You may wish to add references from the library's many databases. This is one of the most efficient ways to add references. To do so, you will want to export the references from a database to your EndNote library. Here are some examples.
Then save it as an RIS file and open it in EndNote. The file may automatically export to EndNote or you may have to click on the downloaded file and tell it to open with the EndNote program.
From an EBSCO database,
Once you click on the folder, you will be taken to a page where you can select the references and export them to your EndNote library.