How can I add materials such as eyes and face?

You can add it by following the steps below.

1. Create a new texture by referring to the eye texture that has already been prepared.
   * The colored parts are white, the shadows are black, and the highlights are transparent colors.
2. In Unity, Add the texture in the following location:
   > CustomizableAnimeGirl\Models\Textures
3. Duplicate materials such as eyes and faces in the following location:
   > CustomizableAnimeGirl\Models\Materials
4. Change the texture of the duplicated material to the newly created one.
5. Select CustomizableAnimeGirl on the scene, and press AutoDetectMaterials in Customize Manager.
6. If it is prefabricated, click ApplyAll in Overrides to apply the changes to the prefab.
7. Complete