If you have your domain bought and hosted on AWS, but would like to use the subdomain for the cluster, you will need to create a new hosted zone in Route 53 and then delegate the new route to this new zone. This is basically about copying the NS servers of your subdomain up to the parent domain in Route 53. Let's assume our domain is mydomain.com; we need to get some information first. Note that the jq command-line tool comes in handy now, when executing aws commands. First, we need the ID of our main parent zone:
$ aws route53 list-hosted-zones | jq '.HostedZones \ | select(.Name=="mydomain.com.") | .Id'
To create a new subdomain, execute the following:
$ aws route53 create-hosted-zone --name ...