How to use the camunda-external-task-client-js.File function in camunda-external-task-client-js

client.subscribe("invoiceCreator", async function({ task, taskService }) {
  // Put your business logic
  // complete the task
  const date = new Date();
  const invoice = await new File({ localPath: "./assets/invoice.txt" }).load();
  const minute = date.getMinutes();
  const variables = new Variables().setAll({ invoice, date });

  // check if minute is even
  if (minute % 2 === 0) {
    // for even minutes, store variables in the process scope
    await taskService.complete(task, variables);
  } else {
    // for odd minutes, store variables in the task local scope
    await taskService.complete(task, null, variables);
  }
});