XYZLoader Example in three.js not working locally

I really hope this question could be solved. And I would really appericate your help.
To reproduce this issue, you only need to download the files I provided below. And open a ternimal then type python3 -m http.server 8000 in the ternimal.
Search localhost:8000 in the web broswer.
The expected output is:
But my output is a empty canvas.
Can anyone help me with this issue? I am glad to provide more details.
Best regards,
George (9.0 KB)
main.css (628 Bytes)
webgl_loader_xyz.html (3.5 KB)
XYZLoader.js (1.8 KB)