How to schedule call to appwrite function ? Call multiple time same function lead to error

Internal curl errors has occurred within the executor! 
Error Number: 111. 
Error Msg: Connection refused
Error Code: 500

export default async ({ req, res, log, error }: Context) => {
  const paperPrices = await fetchPrices();
  const client = new Client();
  const functions = new Functions(client);
  client
    .setEndpoint("ENDPOINT") // Your API Endpoint
    .setProject(process.env.APPWRITE_PROJECT_NAME) // Your project ID
    .setKey(process.env.APPWRITE_API_KEY); // Your secret API key

  function createExecution(startIndex: number, endIndex: number) {
    const payload = {
      startIndex: startIndex,
      endIndex: endIndex,
    };

    return functions
      .createExecution(
        "XXXXX", // functionId
        JSON.stringify(payload), // body
        true, // async (optional)
        "/", // path (optional)
        "POST" // method (optional)
        // {} // headers (optional)
      )
      .then(function (response) {
        log("Success");
      })
      .catch(function (err) {
        error("Error");
      });
  }
  const batchSize = 1000;
  const totalSize = paperPrices.length;
  for (let startIndex = 0; startIndex < totalSize; startIndex += batchSize) {
    const endIndex = Math.min(startIndex + batchSize, totalSize);
    await createExecution(startIndex, endIndex);
    // Need to add a wait time to avoid rate limit
    await new Promise((resolve) => setTimeout(resolve, 500));
  }

  if (req.method === "GET") {
    return res.send("SUCCESS");
  }

export default async ({ req, res, log, error }: Context) => {
  try {
      const { startIndex, endIndex } = JSON.parse(req.body as string);
      const allPrices: TodayPriceFormat[] = await fetchPrices(); // Data from third service
      const prices: TodayPriceFormat[] = allPrices.slice(startIndex, endIndex);
      for (const price of prices) {
        await updatePrices(price); // Launch the update document function
      }
      return res.send("Updated price");
    } catch (err) {
      error("Error");
      return res.send("Failed to update price");
    }
  };

return databases.updateDocument(databaseId, priceCollectionId, docId, doc);