uniapp小程序下载并导出excel

<button @click="confirmExport">导出excel</button>

    confirmExport() {
      let header =  {
          "X-Access-Token": uni.getStorageSync(ACCESS_TOKEN), //自定义请求头信息
        } 
      let url = "http"/......"; // 后端API地址
      uni.request({
          url: url,
          method: "POST",
          // method:"GET",
          header: header,
          responseType: "arraybuffer",
        })
        .then((res) => {
          const now = new Date();
          const fileName = now.toISOString() + ".xlsx";
          const arrayBuffer = res[1].data; // utf-8编码的文件数据
          const base64String = uni.arrayBufferToBase64(arrayBuffer);
          const buffer = uni.base64ToArrayBuffer(base64String);
          let fs = uni.getFileSystemManager();
          const filePath = wx.env.USER_DATA_PATH + "/" + fileName;
          fs.writeFile({
            filePath: filePath,
            data: buffer,
            encoding: "binary",
            success: (res) => {
              console.log("文件保存成功");
              uni.openDocument({
                filePath: filePath,
                fileType: 'xlsx',
                showMenu: true,
                success: (res) => {
                  console.log("文件预览成功");
                  // 构建分享内容
                },
                fail: (error) => {
                  console.error("文件保存失败", error);
                },
              });
            },
          });
        });
    },