It should be printed at the very top of your outward-facing theme, like on the home page. There is a chance that your theme’s CSS could hide or distort the output, so you might have to view your page source to see it.
I like to put a string in front that I know is unique so that I can Ctrl+F and search for the text, like so:
echo '<pre>testdump999: '.print_r($field, true).'</pre>';
There’s a pretty slim chance that “testdump999” will show up anywhere else on its own, so if I can find that then it’s the output I’m looking for.
