Unable to Update to macOS Sonoma on MacBook Pro (Retina, 15-inch, Mid 2015)

Hello Apple Community,

I am facing an issue while trying to update my Xcode to the latest version, Xcode 15. The update process prompts an error stating: "You have macOS 12.7.1. The application requires macOS 13.5 or later."

Upon visiting the Mac App Store and attempting to update to "macOS Sonoma," my MacBook Pro (Retina, 15-inch, Mid 2015) checks for updates but insists it's already up to date with macOS 12.7.1. A pop-up follows, stating, "The requested version of macOS is not available. Please check if your Mac is compatible with this software."

I've confirmed that my hardware should be compatible. Can anyone provide insights or suggestions on why I'm unable to update to the latest OS?

Any help or advice would be greatly appreciated.

Thank you.