Google Sheets Automatic Timestamp Updater on Row Edit

Code.gs

function onEdit() {
  var s = SpreadsheetApp.getActiveSheet();
  if( s.getName() == "Member Admissions Tracker" ) { //checks that we're on the correct sheet
    
    var r = s.getActiveCell(); // Get our active cell
    var column = r.getColumn(); // Get the column of the active cell
    var row = r.getRow(); // Get the row of the active cell
    
    if(row != 1) { // Don't do this for the first row
      if(column != 4) { // Don't do this for the timestamp column
        var firstCell = s.getRange(row, 1) // Get the first cell in this row
        if(firstCell.getValue() != '' ) { // Only update the timestamp if we have something in the first cell of the row
          var cell = s.getRange(row, 4) // Select Timestamp cell for the active row
          cell.setValue(new Date()); // Update the timestamp cell value with the latest date
        }
      }
    }
  }
}