Google Sheets Automatic Update Rook

function storeFollowers(){
    var sheet = SpreadsheetApp.getActiveSheet();
    var datarange = sheet.getDataRange();
    var numRows = datarange.getNumRows();
    var numColumns = datarange.getNumColumns();
    var nextColumn = numColumns + 1;
    sheet.getRange(1, nextColumn).setValue(new Date());
    for (var i=2; i <= numRows; i++){
      var numLikes = sheet.getRange(i, 3).getValue();
      sheet.getRange(i, numColumns + 1).setValue(numLikes);
    }
}
Magnificent Mallard