What am I doing wrong when using onSelectionChange

Question

I found this trigger onSelectionChange(e) on developers.google.com it should set background to red if a single empty cell is selected. I\'m not getting that result with just

Answer 1

UPDATE:

It seems it is fully rolled out to all users. You should be able to get it working without any modification to the code. The e, event object is similar to the onEdit event object.

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onSelectionChange is a recently rolled out feature. Consider waiting a few days for the feature to be rolled out to your specific project and spreadsheet.