Setting WR Trigger to search form

Hello,

I'm trying to set a WR Trigger on a Search Form in order to catch the results before they're displayed. (In the end I would like to use a webreport to display the results HTML with the option to export to Excel.)

Right now my WR is not triggered, even though I have set it to the correct node types and the correct WR Trigger.

Any tips would be greatly appreciated.