deploy in a subfolder

Hi all,
I have a works project in my root of my site.
I need to deploy a copy of project (for future implementations) in a subfolder.
I have copied my root project and I have configured nginx to change root when open new location…
Next I have edited homepage in package.json for the copy to link at subfolder.

Now If I open the subfolder domain, I have a white page.
Do you can help me?