I configured a query to allow drillthrough through the interactions but the option doesn't show up on a dashboard. Why is that?
If on the query level, the setting Interactions > Allow drillthrough is enabled and, on the dashboard level, you can't see the option to Drillthrough, then make sure Allow drillthrough is checked in the data interactivity options.
Someone may have switched off the interactivity options in your dashboard. For more information, see the article: Turning off dashboard and query interactivity.