Nginx configuration for jitsi server + custom app

Hello,
I successfully installed jitsi server on a VPS server and registered a domain name… so the server works! Now, I’d like to play with the the lib-jitsi-meet API so I copied the API example in /var/www/html.
My problem is I cannot configure nginx to make coexist the example script with jitsi server.
After several attempts I configured a fake vrtual host (set in my Windows hosts file) and it works, I can reach the example script… buuuuut I get CORS errors when the library tries to connect to the jitsi server.

# my configuration
server {
    listen 80;
    server_name app.xxxx.it;                          ----> not registered, exists only in my hosts file
    root /var/www/html/xxxx/doc/example;
    index index.html;
}
# jitsi default configuration
server {
    listen 80;
    listen [::]:80;
    server_name streaming.xxxx.it;                ---> is registered

    location ^~ /.well-known/acme-challenge/ {
       default_type "text/plain";
       root         /usr/share/jitsi-meet;
    }
    location = /.well-known/acme-challenge/ {
       return 404;
    }
    location / {
       return 301 https://$host$request_uri;
    }
}
server {
    ...
}

Any help is very apreciate.
Thanks!