Nokia 2 is the lowest priced Nokia smartphone that is now available for purchase in many countries. Many companies just don't provide security updates for their low priced smartphones but HMD Global has promised of providing regular security updates on Nokia 2 and the first security update has been pushed. Nokia 2 has started receiving the November Security update.
The update is 444MB in size and you will be notified of the update. You can also check the manually by going to Settings > About Phone > System Updates.