How to use upload_chunked_stream correctly?

I'm trying to upload a unity 3D model file. The file size exceeds the maximum file size allowed for the free plan.

But I thought that using the upload_chunked_stream + chunk_size could help me solve this problem. So I did the following:

async uploadChunkedStream(file: any, options: any): Promise<any> {
        return new Promise((resolve, reject) => { 
            const { buffer, originalname } = file;
            const public_id = `Unity3D/${originalname}`;

            const uploadStream = cloudinary.uploader.upload_chunked_stream(
                {
                    resource_type: 'raw',
                    chunk_size: 6000000, // 6MB
                    public_id,
                },
                (error: Error, result: UploadApiResponse) => {
                    if (result) {
                        resolve(result);
                    } else {
                        reject(error);
                    }
                },
            );

            streamifier.createReadStream(buffer).pipe(uploadStream);
        });
}

but it didn’t, response:

[
    {
        "done": false,
        "bytes": 7944344,
        "kind": "upload",
        "resource_type": "raw",
        "public_id": "Unity3D/model.unity3d"
    }
]

Can upload_chunked_stream really help me with this problem? Or what am I doing wrong?