http error 401

[Hervé Edorh]

I used django and weasyprint to make an application which print a pdf file with picture and css file which design my pdf file. I used nginx, gunicorn and supervisor to deploy my application. In my intranet all is ok. When i used INTERNET PUBLIC IP ADDRESS to publish it on internet, my pdf file don't show anymore picture and css design. but all the application's static files work well I see my gunicorn log but nothing. I use Nginx to serve my static file.

A log in django give me this

Failed to load stylesheet at http://IP_ADDR/static/css/default.css : HTTPError: HTTP Error 401:
Failed to load image at "http://IP_ADDR/static/image/picture_50x48.png" (HTTPError: HTTP Error 401: )

I d'ont understand what to do because in my internet network it is working well. What is the problem?