my $parser = XML::LibXML->new();
        
        my $doc  = $parser->parse_string($response->content);
        my $root = $doc->documentElement();
        print $root->nodeName, "\n";
        foreach my $node ($root->childNodes){
                print  $node->nodeName, "\n<br>";
        
        
        if ($node->hasAttributes){
                foreach ($node->attributes){
                        printf(" %10s: %-20s\n",$_->name, $_->value);
                        
                }
                
        }
   }

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE SCAN SYSTEM "https://w3.com/example.dtd">
<SERVER value="None">
  <ERROR number="1000">
  fehler aufgetreten
  </ERROR>
</SERVER>