AWS Opensearch Service (1.1) with email alerting (AWS SNS)

Hi everyone, I was trying to make an alerting system that every time a specific value is stored in one OpenSearch index, that triggers an email alarm configured with AWS Simple Notification Service. The problem is that, when I go to create the destination, in the “Alerting” configuration section, it’s supposed to show me the option to integrate it with SNS but it doesn’t, it only shows me 3 options: Slack, custom webhook, and Amazon Chime (as mentioned in their doc: “Compared to OpenSearch, alerting in Amazon OpenSearch Service has some notable differences… OpenSearch Service supports Amazon Simple Notification Service (Amazon SNS) for notifications.”)

Does anyone know what should I do to integrate SNS with the AWS OpenSearch Service? Because also, supposing that it is not possible for any reason, if I wanted to do the same thing, using a Lambda function, it’s nonsense because as OpenSearch is a service hosted in AWS, why should I go to the Internet, to consume an API (also hosted in AWS) with all that implies (time, security, etc.), just to send an alert mail message?

Thanks for your time.