You can include anyone who’s using EndNote 20 (up to 199 people, plus yourself
Share your entire EndNote library, including references, PDFs, and annotations
Decide whether you would like to give your colleague's EndNote Online account 'Read only' or 'Read & Write' permission.
Everyone can add to, annotate and use the library – at the same time
There’s no charge for sharing, no library size limit and no charge for unlimited cloud storage
Sharing Libraries Instructions and video from EndNote
To share a library, you will need an EndNote Online account.
Go to myendnoteweb.com and create an account.
You will also want to:
In your Desktop library
Go to Edit, then preferences
Fill in you username/address and your password
You should also see the location and name of the library you wish to share.
Create your EndNote Online account:

When you have created your account, you can sign in

Your EndNote Online Library will (eventually) look something like this:

Finishing the setup to synchronize EndNote Desktop with EndNote Online
Go to Edie, Preferences, Sync, Apply and Save


sharing libraries

To share with others, go to Edit, then Share
Enter the names of those you wish to share the library with.
They will have access (on their desktop) to the library and with read/write permission may edit or add or delete items

If you see the warning below, you are trying to synch with a library that is not your shared library. Close the library and open the Shared Library.

Sharing libraries
All about sharing libraries from researchsoftware.com, including videos