How do I add debug lines?
At the link you referenced it says you can use Civi::log()-&gt;debug(); this section, so for example Civi::log()-&gt;debug(var_export($my_variable, true));

I'm not sure what you mean by the directory isn't available? This article says how to find it: Where are the &quot;ConfigAndLog&quot; and &quot;templates_c&quot; directories?