To download the full Unreal Engine 4.27 offline installer, you generally need to access it through specific official channels, as it is not provided as a standard public direct-download link like the Epic Games Launcher Official Offline Installer Access For Subscription Holders:

Offline Build: Once Setup.bat finishes, the folder is now a "Full Offline Installer." Move it to your offline PC.

Standard users who cannot access the official offline installer must use the following methods:

If you do not have an organization account, you can still achieve an offline setup through these community-standard methods: