agroshel

const baseURL = 'https://iss.moex.com//iss/history/engines/stock/markets/index/securities/RGBITR.json';

const params = new URLSearchParams([
  [ 'sort_order', 'desc' ],
  [ 'iss.meta', 'off' ],
  [ 'iss.only', 'history' ],
  [ 'history.columns', 'TRADEDATE,CLOSE' ],
]);

fetch(`${baseURL}?${params}`)
  .then(r => r.json())
  .then(r => {
    new Chart(document.querySelector('#chart'), {
      type: 'line',
      data: { 
        labels: r.history.data.map(n => n[0]),
        datasets: [ {
          label: 'hello, world!!',
          data: r.history.data.map(n => n[1]),
        } ],
      },
    });
  });

fetch(`${baseURL}?${params}`)
  .then(r => r.json())
  .then(({ history: { data } }) => {
    chart.data.labels = data.map(n => n[0]);
    chart.data.datasets[0].data = data.map(n => n[1]);
    chart.update();
  });

const chart = new Chart(document.querySelector('#chart'), {
  type: 'line',
  data: { 
    labels: [],
    datasets: [ {
      label: 'hello, world!!',
      data: [],
    } ],
  },
});