I am trying to upgrade from M2 2.3.1 Community edition to Enterprise edition. I followed this official guide https://devdocs.magento.com/guides/v2.3/comp-mgr/upgrader/ce-ee-upgrade-start.html
But when I click System Upgrade, I get message you are already using latest version
but it is latest for community edition and I need enterprise edition. I have already updated EE access keys in Magento Admin. How can I upgrade?