Or go directly to the list of available update sites for different Embedded Workbench targets. You will need to select a site which matches the IAR Embedded Workbench installation that you want to integrate in Eclipse.
CDT in Eclipse 2020-06 currently has an issue running against Java 8. The workaround is to disable "Verify provisioning operation is compatible with currently running JRE" in Windows -> Preferences -> Install/Update. See the CDT release notes at https://wiki.eclipse.org/CDT/User/NewIn911 for further details.
For more information about IAR Embedded Workbench for Eclipse, visit http://iar.com/eclipse.