How to upgrade from e/OS 1.7 to 2.0?

It would seem you are running /e/OS based on Android 11 (R) then, based on the versions available for download … here’s how to confirm and give us exact info to work with: [HOWTO] Give complete /e/OS version info easily for support, answers, comparison etc

If so, you would be on the right track with a new install, as there’s no other way to get your device any further.
As for the Easy Installer … Howto troubleshoot issues with the easy-installer