EndNote 21 is the first version to integrate with Google Docs. As of August 2023 this is new and evolving. Steps to add the EndNote CWYW tool into your Google Docs toolbar at this link https://support.clarivate.com/Endnote/s/article/Google-Docs-CWYW?language=en_US.
EndNote versions 20 and below do not recommend working with Google Docs on Google Drive. There is not a CWYW tool available for EndNote 20 or previous versions.
However, there is a workaround described in the boxes below, that seems to work with Chrome.