how to upload textures to the 3d product models

[ZEROPlus_Simon]

how do i upload my textures for my 3d models on my stores product page? 

the official documentation says:

For a GLB file, you need to export the following texture maps:

• diffuse
• normal
• a single map with occlusion, roughness, and metalness mapped to the red, green, and blue channels respectively
• emissive (optional)

however i dont see a way to add these textures maps anywhere