This glTF file is not being exported correctly by Sketchfab. The base color of the glass material has no transparency. I’d suggest fixing it in Blender, you’ll have to replace black areas of the texture with transparency with Imagemagick:
convert Glass_baseColor.png -transparent black Glass_baseColorOut.png
and then probably also reduce the alpha value to 0.5 or so in Blender with a Multiply node. Here’s a quick edited version, compressed most images with JPEG for size:
I will try your way, but I have very little experience in blender and I created the model in other programs.
Can I somehow replace textures/materials when uploading a model or something?