how to get blob return from canvas

Question

I want to get blob value return, but it's return nothing but consoling value

canvas.toBlob(
            (blob) => {
                // Handle the compressed image. es. upload or save in local state
                res = new File([blob], file.name, { type: file.type });
                console.log(res)
                return res;
            },
            MIME_TYPE,
            QUALITY
        );