How do I track packages in Google Sheets automatically?

// Extensions → Apps Script. Project Settings → Script properties: LASTSCANNED_KEY = lsk_live_...
// Sheet "Tracking": A tracking number | B carrier | C status | D newest scan (UTC) | E newest scan | F estimated delivery
function onOpen() {
  SpreadsheetApp.getUi().createMenu("Tracking").addItem("Refresh now", "refreshTracking").addToUi();
}

function refreshTracking() {
  const key = PropertiesService.getScriptProperties().getProperty("LASTSCANNED_KEY");
  const sheet = SpreadsheetApp.getActive().getSheetByName("Tracking");
  const count = sheet.getLastRow() - 1;
  if (count < 1) return;
  const rows = sheet.getRange(2, 1, count, 3).getValues()
    .map((r, i) => ({ number: String(r[0]).trim().toUpperCase(), status: r[2], row: i + 2 }))
    .filter((r) => r.number && r.status !== "delivered" && r.status !== "returned");

  for (let i = 0; i < rows.length; i += 35) {
    const batch = rows.slice(i, i + 35);
    const url = "https://api.lastscanned.com/v1/track?numbers=" + encodeURIComponent(batch.map((r) => r.number).join(","));
    const res = UrlFetchApp.fetch(url, { headers: { Authorization: "Bearer " + key }, muteHttpExceptions: true });
    if (res.getResponseCode() !== 200) throw new Error(res.getContentText());
    JSON.parse(res.getContentText()).results.forEach(({ result, error }, j) => {
      const last = result && result.events[0]; // newest first
      sheet.getRange(batch[j].row, 2, 1, 5).setValues([[
        result ? result.carrier : "",
        result ? result.status : error.code,
        last ? last.timestamp : "",
        last ? last.description : "",
        (result && result.estimatedDelivery) || "",
      ]]);
    });
  }
}

function installHourlyTrigger() {
  ScriptApp.newTrigger("refreshTracking").timeBased().everyHours(1).create();
}

// Optional: watched numbers are re-checked for you and listed at app.lastscanned.com/watches.
function watchRows() {
  const key = PropertiesService.getScriptProperties().getProperty("LASTSCANNED_KEY");
  const sheet = SpreadsheetApp.getActive().getSheetByName("Tracking");
  const numbers = sheet.getRange(2, 1, Math.max(sheet.getLastRow() - 1, 1), 1).getValues()
    .map((r) => String(r[0]).trim()).filter(Boolean);
  for (let i = 0; i < numbers.length; i += 100) {
    UrlFetchApp.fetch("https://api.lastscanned.com/v1/watches", {
      method: "post",
      contentType: "application/json",
      headers: { Authorization: "Bearer " + key },
      payload: JSON.stringify({ trackingNumbers: numbers.slice(i, i + 100), metadata: { sheet: "Tracking" } }),
    });
  }
}