wx.cloud.callFunction({
      name: 'test',
      data: {
        test: wx.cloud.CDN({
          type: 'filePath',
          filePath: wx.base64ToArrayBuffer(res.data),
        })
      },
      success: res => {
      },
      fail: err => {
      },
      complete: res => {
        console.log(res)
      }
    })

Uncaught (in promise) TypeError: wx.cloud.CDN is not a function

怎么解决?