nginx urldecode

location ~* ^/internal_redirect/(.*?)/(.*?)/(.*) {
                internal;
                resolver 8.8.8.8;
             
                set $srv  $1;
                set $fn  $2;
                set $durl $3;
 
                proxy_set_header Host $srv;
 
                proxy_hide_header Content-Disposition;
                add_header Content-Disposition 'attachment; filename="$fn"';
                proxy_pass http://$durl;
                proxy_max_temp_file_size 0;
        }