I'm trying to convert .obj with several .png (textures) files into .usdz through Reality Converter but it isn't working. It'll take the object, but when I put the png files under the material folder, nothing happens?
Any suggestions?
I end up with a blank/white object.

I encountered the same issue myself, but don't worry. In the main preview, it doesn't reflect the texture after adding a
pngfile, but if you watch the small preview on the left side (click the Models button), it correctly displays the texture. Therefore, if you export it, theusdzfile is exported correctly with the texture.