Copy the EFI folder from the OpenCore X64 directory to the root of your USB.

The offline installer only works if your OpenCore configuration is tailored to your specific hardware (CPU, GPU, and Motherboard). Essential Kexts

This will download the BaseSystem.dmg and BaseSystem.chunklist files. Phase 3: Preparing the USB Drive

Format your target SSD as APFS with a GUID Partition Map .

Move the downloaded BaseSystem.dmg and BaseSystem.chunklist into this folder.

Root of USB -> Create a folder named com.apple.recovery.boot .

The latest release from Acidanthera’s GitHub. ProperTree: A cross-platform plist editor. Phase 2: Downloading the macOS Image