There are two ways to create in-text citations and a formatted bibliography in Google Docs using EndNote.
To add a citation to your Google Doc, highlight the reference in your EndNote Library, then drag and drop or copy and paste the citation into your Google Doc.
Once you finish adding citations, download your Google Doc as a Rich Text Format (.rtf) file. Then go to EndNote, and go to Tools -> Format Paper -> Format Paper and choose the file from your computer.
In the popup box, check your citations and choose your citation style.
Click the Format button to save your document.The default is the name of the document plus the citation style. You can rename the file. After you save it, upload the document to Google Docs. Check that "Convert upload files to Google Docs format" is turned on in your settings.