Comience con las etiquetas de los objetos de Amazon S3 mediante un AWS SDK

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

    /// <summary>
    /// This example shows how to work with tags in Amazon Simple Storage
    /// Service (Amazon S3) objects.
    /// </summary>
    public class ObjectTag
    {
        public static async Task Main()
        {
            string bucketName = "doc-example-bucket";
            string keyName = "newobject.txt";
            string filePath = @"*** file path ***";

            // Specify your bucket region (an example region is shown).
            RegionEndpoint bucketRegion = RegionEndpoint.USWest2;

            var client = new AmazonS3Client(bucketRegion);
            await PutObjectsWithTagsAsync(client, bucketName, keyName, filePath);
        }

        /// <summary>
        /// This method uploads an object with tags. It then shows the tag
        /// values, changes the tags, and shows the new tags.
        /// </summary>
        /// <param name="client">The Initialized Amazon S3 client object used
        /// to call the methods to create and change an objects tags.</param>
        /// <param name="bucketName">A string representing the name of the
        /// bucket where the object will be stored.</param>
        /// <param name="keyName">A string representing the key name of the
        /// object to be tagged.</param>
        /// <param name="filePath">The directory location and file name of the
        /// object to be uploaded to the Amazon S3 bucket.</param>
        public static async Task PutObjectsWithTagsAsync(IAmazonS3 client, string bucketName, string keyName, string filePath)
        {
            try
            {
                // Create an object with tags.
                var putRequest = new PutObjectRequest
                {
                    BucketName = bucketName,
                    Key = keyName,
                    FilePath = filePath,
                    TagSet = new List<Tag>
                    {
                        new Tag { Key = "Keyx1", Value = "Value1" },
                        new Tag { Key = "Keyx2", Value = "Value2" },
                    },
                };

                PutObjectResponse response = await client.PutObjectAsync(putRequest);

                // Now retrieve the new object's tags.
                GetObjectTaggingRequest getTagsRequest = new GetObjectTaggingRequest()
                {
                    BucketName = bucketName,
                    Key = keyName,
                };

                GetObjectTaggingResponse objectTags = await client.GetObjectTaggingAsync(getTagsRequest);

                // Display the tag values.
                objectTags.Tagging
                    .ForEach(t => Console.WriteLine($"Key: {t.Key}, Value: {t.Value}"));

                Tagging newTagSet = new Tagging()
                {
                    TagSet = new List<Tag>
                    {
                        new Tag { Key = "Key3", Value = "Value3" },
                        new Tag { Key = "Key4", Value = "Value4" },
                    },
                };

                PutObjectTaggingRequest putObjTagsRequest = new PutObjectTaggingRequest()
                {
                    BucketName = bucketName,
                    Key = keyName,
                    Tagging = newTagSet,
                };

                PutObjectTaggingResponse response2 = await client.PutObjectTaggingAsync(putObjTagsRequest);

                // Retrieve the tags again and show the values.
                GetObjectTaggingRequest getTagsRequest2 = new GetObjectTaggingRequest()
                {
                    BucketName = bucketName,
                    Key = keyName,
                };
                GetObjectTaggingResponse objectTags2 = await client.GetObjectTaggingAsync(getTagsRequest2);

                objectTags2.Tagging
                    .ForEach(t => Console.WriteLine($"Key: {t.Key}, Value: {t.Value}"));
            }
            catch (AmazonS3Exception ex)
            {
                Console.WriteLine(
                        $"Error: '{ex.Message}'");
            }
        }
    }