Doug just means you need to split up the operation. You can still do what you want.
Calculate #1 is your pulldata(@layer)
E.g., pulldata("@layer", "getValueAt", "attributes.Name", "https://services2.arcgis.com/sBoGufkdR7jFytOm/arcgis/rest/services/shedMap_WFL1/FeatureServer/8", ${Location_of_Project}, "")
Calculate #2 is your IF statement.
E.g., if(${pulldata_calc}='','Not in a Priority Area',${pulldata_calc})
Not saying these calculates are correct. They are just examples. This is generally what you'd be looking to do.