SNS

You can create an SNS client that can send messages using the AmazonSimpleNotificationServiceClient in the Amazon.SimpleNotificationService library. The client takes credentials from accessing the topic and an region where the topic is configured. You need to also import the Amazon namespace to use the RegionEndpoint enum.

var snsClient = new AmazonSimpleNotificationServiceClient(awsCredentials, RegionEndpoint.EUWest1);

You can send a message to an SNS topic using the PublicAsync method on your SNS client. This takes a PublishRequest object that requires a message and an ARN of the topic the message is being sent to.

var response = await snsClient.PublishAsync(
    new PublishRequest
    {
        Message = "Message",
        TopicArn = "<ARN_OF_TOPIC>"
    }
);