The documentation seems very light about this part but it says the text field should contain a variable name, so maybe try to define a boolean variable in your code and put its name in this field to see if you get different results?
echo prawn
The documentation seems very light about this part but it says the text field should contain a variable name, so maybe try to define a boolean variable in your code and put its name in this field to see if you get different results?
But I would have done the same as you given it's expecting an "expression"