AwaRyo

I think the materials have too much complicated nodes to be compatible for gltf export. And also the model uses too much materials for each objects.
You need to simplify all shaders to see textures, for example, like the black framed “principled BSDF shader” of the attached image.

2nd image, you can see hair texture which I simplified one of the hair materials.

I think your shader has no problem.
It may be an HDR highlight clipping. you can try “Light Probe(fast)” setting in “IBL Environment Mode” in Verge3D Settings.