Override the Existing File Upload on Frappe

Hi all,
I have this custom API to upload the file to the S3 bucket. I need to override the existing file upload. By default, I need to use the S3 bucket for file uploads, below is my sample code

@frappe.whitelist()
def upload_file_to_s3():

uploaded_files = frappe.request.files.getlist("file")  
if not uploaded_files:
    frappe.throw("No files found in request")

s3_client = boto3.client(
    "s3",
    aws_access_key_id=AWS_ACCESS_KEY,
    aws_secret_access_key=AWS_SECRET_KEY,
    region_name=S3_REGION
)

file_urls = []

for filedata in uploaded_files:
    filename = secure_filename(filedata.filename)
    file_content = filedata.stream.read()
    unique_filename = f"{random_string(10)}-{filename}"
    s3_key = f"frappe-uploads/{unique_filename}"

    try:
        # Upload file without ACL
        s3_client.put_object(
            Bucket=S3_BUCKET_NAME,
            Key=s3_key,
            Body=file_content,
            ContentType=filedata.content_type
        )

        s3_url = f"https://{S3_BUCKET_NAME}.s3.{S3_REGION}.amazonaws.com/{s3_key}"

        # Save file URL in Frappe
        file_doc = frappe.get_doc({
            "doctype": "File",
            "file_name": filename,
            "file_url": s3_url,
            "is_private": 1
        })
        file_doc.insert(ignore_permissions=True)
        frappe.db.commit()

        file_urls.append(s3_url)

    except Exception as e:
        frappe.logger().error(f"Error uploading {filename} to S3: {str(e)}")
        frappe.throw(f"Failed to upload {filename} to S3. {str(e)}")

return {"message": "Files uploaded successfully", "file_urls": file_urls}