Blob is returning empty string after creation

I have an extremely large JSON string that I need to send to my server. I encountered payloadTooLargeError when I tried sending the JSON string directly.

So, I decided to send it as a blob instead. But unfortunately, after creating the blob, the blob is returning an empty string.

Here is how I created the blob:

 let largeContentPayload = {
        data: {
            'batch_id': batchId,
            content: extremelyLargeJSON
        }
    };
    const largeContentStringified = JSON.stringify(largeContentPayload);
    const largeContentBlob = new Blob([largeContentStringified], {
        type: 'application/json;charset=utf-8'
    });
    console.log(largeContentBlob); //This is only returning size and type, the JSON string is not there
    const blobUrl = URL.createObjectURL(largeContentBlob);
    let requestBody = new FormData();
    let blob = await fetch(blobUrl).then(r => r.blob());
   

How can this be resolved?