Are you looking to install 10.3.3 because you are running an older macOS like High Sierra or Sierra?
Apple never released a trial for version 10.3.3. The current 90-day trial (as of 2025) is for Logic Pro 10.8 or newer.
In this article, we’ll cover everything you need to know about the Logic Pro X 10.3.3 DMG download—what it includes, system requirements, how to install it safely, and alternative legal sources. Logic Pro X 10.3.3 DMG Download
Note: If you have never purchased Logic Pro, you must first buy it on a Mac running a newer macOS version. Once it is in your purchase history, you can follow the steps above on your older machine. How To Download older version of Logic - Apple Communities
Here’s a sample write-up:
In the context of macOS, a DMG (Disk Image) is the standard file format used to distribute and install software. Historically, users looking for the "Logic Pro X 10.3.3 DMG" were often searching for a way to roll back their systems or install the software on older hardware that could not support the latest version of Logic.
If you cannot find a safe download or your Mac cannot run this version, consider these alternatives: Are you looking to install 10
Only if you have a Time Machine backup or a standalone DMG saved from when you originally downloaded 10.3.3. The App Store does not offer downgrades.