Problem with add new attribute in table with BOTO3 on python

Question

I have table with two attribute 'first_interval' and 'second_interval' and I must add new column 'date', but I cant do it.

Connect to my table:
table = database.Table('table231')
database = boto3.resource(
    'dynamodb',
    endpoint_url = config.USER_STORAGE_URL,
    region_name = 'ru-central1',
    aws_access_key_id = config.AWS_PUBLIC_KEY,
    aws_secret_access_key = config.AWS_SECRET_KEY
)

I used update_item but I took error 'botocore.exceptions.ClientError: An error occurred (ValidationException) when calling the UpdateItem operation: Missing value for required parameter "first_interval"'