DigitalOcean Presigned Post URL not getting the ACL as public-read

Question

I'm trying to upload images to a Digital Ocean space from my application. These images are public and I am able to upload the images but they are getting uploaded as private

I have tried adding x-amz-acl variable to public-read after I get the presigned POST values but it is still getting uploaded as private.

I have also tried giving the conditions parameter as specified below but got the error as: policy can not recognise variable acl

Here is my code

    session = boto3.session.Session()

    # Generate a presigned S3 POST URL
    client = session.client('s3',
                            config=botocore.config.Config(s3={'addressing_style': 'virtual'}),
                            region_name=os.getenv('DEFAULT_REGION'),
                            endpoint_url='https://sgp1.digitaloceanspaces.com',
                            aws_access_key_id=os.getenv('S3_ACCESS_KEY'),
                            aws_secret_access_key=os.getenv('S3_SECRET_KEY'))

    try:
        response = client.generate_presigned_post(Bucket=os.getenv('BUCKET_NAME'),
                                                  Key=object_name,
                                                  # Conditions=[{"ACL": "public-read"}],
                                                  ExpiresIn=expiration)

    except ClientError as e:
        logging.error(e)
        return None

    # The response contains the presigned URL and required fields
    return response

After getting the response from my application I have been adding another multipart/form field:

x-amz-acl: public-read

But still nothing is helping. Would really appreciate if anyone help me solve it!