擴充功能>Apps Script
第一列輸入皆可

function onEdit(e) {
  var sheet = e.source.getActiveSheet();
  var range = e.range;
  var columnIndex = range.getColumn();
  var rowIndex = range.getRow();
  
  if (rowIndex === 1 && range.getValue() !== "") {
    var nextRow = findNextEmptyRow(sheet, columnIndex);
    var nextCell = sheet.getRange(nextRow, columnIndex);
    nextCell.setValue(range.getValue());
    range.clearContent();
  }
}

function findNextEmptyRow(sheet, columnIndex) {
  var data = sheet.getRange(1, columnIndex, sheet.getLastRow()).getValues();
  
  for (var i = 0; i < data.length; i++) {
    if (data[i][0] === "") {
      return i + 1;
    }
  }
  
  return data.length + 1;
}