Ah, please include the text version of the output too, i.e., the output without the HTML tags. We use this for the API. So it should be something like:

```perl
return $text, html => $html, heading => "Latex command ($heading)";
```

And you'd see this when you run `duckpan query`:

```perl
DDG::ZeroClickInfo  {
    Parents       WWW::DuckDuckGo::ZeroClickInfo
    public methods (1) : new
    private methods (0)
    internals: {
        answer        "Command: \sum_{lower}^{upper}
                       Usage: $\sum{i=0}^{10} x^{2}$",
        answer_type   "Latex",
        heading       "Latex command (summation)",
        html          "<i>Command:</i> \sum_{lower}^{upper} <br> <i>Usage:</i> $\sum{i=0}^{10} x^{2}$",
        is_cached     1,
        is_unsafe     0
    }
}
```