You can download official FL Studio installers directly from the Image-Line Download Page .

You may need to log in to your Image-Line Account to download legacy versions. 🛠️ Installation Tips for macOS Locating FL Studio Installation Files

If you specifically need an older build (like the one associated with the 20.8.3 era), you must access the official archives. FL Studio Forum Archive

Typically distributed as a .dmg installer, though .zip archives are sometimes used for beta or specific archive builds. Legacy and Specific Builds