Upgrading from IOS 12 beta 13 to IOS 12 stable release

Hello everybody
I were a beta tester of IOS 12 for the last two or three weeks. On my iPhone under settings, under general and under software update I received the message: "IOS 12.0. Your software is up to date." I did not though received a message to upgrade to the stable version of IOS 12. Somehow I misunderstood some of the information in the IOS beta guide. Do I have to now connect my iPhone to my computer and within iTunes restore it back to IOS 11 and upgrade to IOS 12 from there? Is this correct? I uninroled my device already from the beta program.