请问 小程序直传 oss 的方式，现在能 Work么？

请问 小程序直传 oss 的方式，现在能 Work么？

my.chooseImage({
      chooseImage: 1,
      success: res => {
        const path = res.apFilePaths[0];
        console.log(path)
        var key = 'image.jpg'
        my.uploadFile({
            url: 'https://ocr-image-bucket.oss-cn-shanghai.aliyuncs.com', //ocr image bucket host
            fileType: 'image',
            fileName: key,
            filePath: path,
            formData: {
                name: path,
                key: '${filename}',
                policy: '<my-policy>',
                OSSAccessKeyId: '<my-OSSAccessKeyId>',
                success_action_status: '200',
                signature: '<my-signature>'
            },
            success: (res) => {
              my.alert({ content: 'success info: ' + res.data });
            },
        });
});

为什么我返回400的错误？POST requires exactly one file upload per request. 只上传一个文件