Use PutBucketNotificationConfiguration com um AWS SDK ou CLI

    using System;
    using System.Collections.Generic;
    using System.Threading.Tasks;
    using Amazon.S3;
    using Amazon.S3.Model;

    /// <summary>
    /// This example shows how to enable notifications for an Amazon Simple
    /// Storage Service (Amazon S3) bucket.
    /// </summary>
    public class EnableNotifications
    {
        public static async Task Main()
        {
            const string bucketName = "amzn-s3-demo-bucket1";
            const string snsTopic = "arn:aws:sns:us-east-2:0123456789ab:bucket-notify";
            const string sqsQueue = "arn:aws:sqs:us-east-2:0123456789ab:Example_Queue";

            IAmazonS3 client = new AmazonS3Client(Amazon.RegionEndpoint.USEast2);
            await EnableNotificationAsync(client, bucketName, snsTopic, sqsQueue);
        }

        /// <summary>
        /// This method makes the call to the PutBucketNotificationAsync method.
        /// </summary>
        /// <param name="client">An initialized Amazon S3 client used to call
        /// the PutBucketNotificationAsync method.</param>
        /// <param name="bucketName">The name of the bucket for which
        /// notifications will be turned on.</param>
        /// <param name="snsTopic">The ARN for the Amazon Simple Notification
        /// Service (Amazon SNS) topic associated with the S3 bucket.</param>
        /// <param name="sqsQueue">The ARN of the Amazon Simple Queue Service
        /// (Amazon SQS) queue to which notifications will be pushed.</param>
        public static async Task EnableNotificationAsync(
            IAmazonS3 client,
            string bucketName,
            string snsTopic,
            string sqsQueue)
        {
            try
            {
                // The bucket for which we are setting up notifications.
                var request = new PutBucketNotificationRequest()
                {
                    BucketName = bucketName,
                };

                // Defines the topic to use when sending a notification.
                var topicConfig = new TopicConfiguration()
                {
                    Events = new List<EventType> { EventType.ObjectCreatedCopy },
                    Topic = snsTopic,
                };
                request.TopicConfigurations = new List<TopicConfiguration>
                {
                    topicConfig,
                };
                request.QueueConfigurations = new List<QueueConfiguration>
                {
                    new QueueConfiguration()
                    {
                        Events = new List<EventType> { EventType.ObjectCreatedPut },
                        Queue = sqsQueue,
                    },
                };

                // Now apply the notification settings to the bucket.
                PutBucketNotificationResponse response = await client.PutBucketNotificationAsync(request);
            }
            catch (AmazonS3Exception ex)
            {
                Console.WriteLine($"Error: {ex.Message}");
            }
        }
    }

Como habilitar as notificações especificadas em um bucket

O exemplo de put-bucket-notification-configuration a seguir aplica uma configuração de notificação a um bucket chamado my-bucket. O arquivo notification.json é um JSON documento na pasta atual que especifica um SNS tópico e um tipo de evento a ser monitorado.

aws s3api put-bucket-notification-configuration \
    --bucket my-bucket \
    --notification-configuration file://notification.json

Conteúdo de notification.json:

{
    "TopicConfigurations": [
        {
            "TopicArn": "arn:aws:sns:us-west-2:123456789012:s3-notification-topic",
            "Events": [
                "s3:ObjectCreated:*"
            ]
        }
    ]
}

O SNS tópico deve ter uma IAM política anexada que permita que o Amazon S3 publique nele.

{
    "Version": "2008-10-17",
    "Id": "example-ID",
    "Statement": [
        {
            "Sid": "example-statement-ID",
            "Effect": "Allow",
            "Principal": {
                "Service": "s3.amazonaws.com"
            },
            "Action": [
                "SNS:Publish"
            ],
            "Resource": "arn:aws:sns:us-west-2:123456789012::s3-notification-topic",
            "Condition": {
                "ArnLike": {
                    "aws:SourceArn": "arn:aws:s3:*:*:my-bucket"
                }
            }
        }
    ]
}