The version is a placeholder used by the final standalone iTunes installers (like version 12.8.3) to signify that they are only compatible with macOS High Sierra (10.13) or older. If your Mac is running Monterey, Ventura, Sonoma, or newer, these installers will fail because the operating system already has the newer, integrated versions of these tools. How to Proceed Based on Your Needs
If you are running macOS High Sierra (10.13), iTunes is included with the system, but you may need to update it. itunes macos 10.13.99 download
Ensure your Mac is fully updated to via the App Store. The version is a placeholder used by the