upgraded iCloud Notes
If you upgrade your account in the Notes app on a device with iOS 9 or later or OS X 10.11 or later, you see upgraded notes on iCloud.com. To see which version of Notes you have, look for one of the following:
If you’re using upgraded notes, you see a Checklist button and a Format button in the Notes toolbar. You also see a folder list on the left.
If you’re not using upgraded iCloud notes, you see Email and Delete in the Notes toolbar.
Once you upgrade, you can view your notes on iCloud.com and your devices with iOS 9 or later and OS X 10.11 or later that are signed in with the same Apple ID. If you also have devices with earlier versions of iOS or OS X, you don’t see your upgraded notes on those devices.
If you’re not using upgraded notes, you can also view your notes in Microsoft Outlook on your Windows computer with the iCloud for Windows app.
See the Apple Support article Upgrade your Notes app.