Cloudwatch SNS Notification for SMSMonthToDateSpentUSD

I am interested in creating a cloudwatch alert for monthly spending. Cloudwatch provides this “SMSMonthToDateSpentUSD” from UI. But how I set this through serverless.yaml ?..

I looked into serverless-plugin-aws-alerts but was not sure how do I use this “SMSMonthToDateSpentUSD” with it,