You will need to install the EndNote Plug-In for Apple Pages here: https://support.apple.com/kb/DL2014?locale=en_ZA
ADD A CITATION
If you have the EndNote plug-in, you can use EndNote to add a citation. Citations are added to an automatically updating bibliography at the end of the document.
Click where you want the citation to appear.
To group the citation with another one, place the insertion point right in front of, or right after, the existing citation.
Click in the toolbar, then choose EndNote Citation.
EndNote opens, and the Find window appears.
Enter text in the Find Citation field, then press Return to search your EndNote library for corresponding citations.
Select options using the controls in the Find EndNote Citations window to define how the citation appears in your document.
If you want the citation to appear only in the bibliography and not in the document, select “In Bibliography only”.
Select a citation from the list, enter a page range (if needed), then click Insert.
The citation is added to your document at the insertion point. If you didn’t select “In Bibliography only”, a bibliography field is added at the end of your document.