When you use EndNote's Cite While You Write (CWYW) function to add citations to your document, you are adding a lot of coding to the document to make the citations and references work. If you open your EndNote formatted Word documents in a web-based word processor (e.g. Google Docs, or the web based version of Word in Microsoft Teams / SharePoint / OneDrive) you can damage this coding and corrupt your document.
The desktop app, e.g. the Word software loaded onto the hard-drive of your laptop, is more stable with EndNote.
It's ok to store your documents in OneDrive, but always open and work with your EndNote formatted Word documents using the desktop app.
EndNote has a Cite While You Write (CWYW) function that allows you to insert citations for sources from your EndNote library into your document. It automatically builds your reference list from these citations. You can also create an independent list of selected references.
Inserting, editing and deleting citations tab, and the Editing and working with your document tab have more information on how to do this.
EndNote's Cite While You Write (CWYW) can also be used with Pages for Mac.
There is a plug-in you can install to make EndNote work with Pages on a Mac. You need EndNote X6 or a later version.
A video you can watch to get an overiew of CWYW for Pages