Explain Plan options not available

I'm connected to an InterSystems Caché database via JDBC using DataGrip 2019.2.1.  I have tried following the direction of several other posts related to the use of the "Explain Plan" and "Explain Plan (raw)" options, but those are not available when I right-click my query, and prepending my query with "Explain" does not work either.  Not sure if it's meant to be present at all times, but I also don't see a "Plan" tab next to the "Result" tab in the output window.

Is this feature not supported for InterSystems Caché databases, or via the method I'm using to connect?