fileUploadForm = (req, folder) => {
  const frm = form(
    {
      action: "/files/upload",
      method: "post",
      enctype: "multipart/form-data",
    },
    csrfField(req),
    label(req.__("Upload file(s)")),
    input({
      name: "file",
      class: "form-control ms-1 w-unset d-inline",
      type: "file",
      onchange: "handle_upload_file_change(form)",
      multiple: true,
    }),
    folder &&
      input({
        id: "uploadFolderInpId",
        type: "hidden",
        name: "folder",
        value: folder,
      })
  );
  return frm;
}
File upload form (for admin)
@param {object} req
@param folder
@returns {Form}