Hi@akhtar,
First, you need to give the public access to the bucket. To create an endpoint for an Amazon S3 source, you can use the below command.
$ aws dms create-endpoint --endpoint-type source --engine-name s3 --endpoint-identifier src-endpoint --s3-settings file://s3-settings.json
Want to learn more about AWS DMS? Check out this blog on AWS Database Migration Service.