I don't pack the textures into the Blender file, for optimization reasons. But they can be very easily extracted from the UnityPackage file by using this tool. https://github.com/Cobertos/unitypackage_extractor?tab=readme-ov-file
Check Lammy's Usage Guide for any further information on how to find or link the textures.
The provided Blender file is mainly formatted for avatar modification purposes.