Could you tell me how to keep a log of a certain cell (in which google finance is embedded ) everyday by using GAS?

My ideal log is below.

Sep 10 ~USD (Extracted from H12 in spread sheet)

Sep 11 ~USD

Sep 12 ~USD

Please help me....

I know how to keep a log of constant but I don't know how to extract the value of a certain cell in GAS script and keep a log of it. enter image description here

This is the code.

const setDataLastRow = () => {
  //シートを指定
  const sheet = SpreadsheetApp.getActiveSheet();
  //最終行を取得
  const lastRow = sheet.getLastRow();

  //今日の日付
  const today = new Date();
  //入力する内容
  const contents = "Constant";
  //スプレッドシートに入力するデータ
  const inputData = [today, contents];

  //入力する行
  const inputCell = sheet.getRange(lastRow + 1, 1, 1, inputData.length);
  //データの入力
  inputCell.setValues([inputData]);
}