EndNote offers both a desktop and an online component.
With EndNote Online you can synchronise the references in your desktop library to your online library for remote access, and share your library with other EndNote users.
An EndNote Online library can contain an unlimited number of references and attachments.
Register or log in to EndNote Online here.
Clarivate EndNote Online Guide
Synchronising your library
To sync your desktop library with your online library, once you have your account set up, go into EndNote preferences on your desktop application, choose Edit → Preferences → Sync
Enter your EndNote Online Account Credentials and hit 'Apply'.
Clarivate Library Syncing in EndNote 20
Your account details for EndNote Online and Web of Science(WoS) must be exactly the same (since WoS is now maintained by Clarivate Analytics - as is Publons). If they are not in sync you will get this message: “Invalid email/password. Please try again”
If you have different passwords: