微信小程序${wx.env.USER_DATA_PATH}在哪

var FileSystemManager = wx.getFileSystemManager()
      FileSystemManager.writeFile({
        filePath: `${wx.env.USER_DATA_PATH}/hello.txt`,
        data: data.Body,
        encoding: 'utf8',
        success(res) {
          console.log(res)
        },
        fail(res) {
          console.error(res)
        }
      })