How to use if condition for specific empty column filter in Google Sheets for macro (google-sheets, filter, if, else, spreadsheet, script)?

I don't know how to use only the e column filter for the if condition. Here is the code that isn't working.

        function myFunction() {
          if (SpreadsheetApp.getActive().getActiveSheet().getRange('E1').getFilter() == null) {
            var spreadsheet = SpreadsheetApp.getActive();
            var criteria = SpreadsheetApp.newFilterCriteria()
            .whenCellNotEmpty()
            .build();
            spreadsheet.getActiveSheet().getFilter().setColumnFilterCriteria(5, criteria);
            spreadsheet.getRange('E1').activate();
            spreadsheet.getCurrentCell().offset(2, 0).activate();
          }
          else {
            var spreadsheet = SpreadsheetApp.getActive();
            var criteria = SpreadsheetApp.newFilterCriteria()
            .build();
            spreadsheet.getActiveSheet().getFilter().setColumnFilterCriteria(5, criteria);
            spreadsheet.getRange('B1').activate();
            spreadsheet.getCurrentCell().offset(2, 0).activate();
          }
        }