Setup a DNS hosted zone in Route53 in AWS.

Go to Route 53
Create a Hosted Zone
Enter:

• Domain name e.g. jonahblessy.com
• Type as Public hosted zone

AWS automatically creates:

• NS (Name Server) records
• SOA (Start of Authority) record

Add DNS Records
Inside the hosted zone Create A Record (IPv4)

• Name:www
• Type: A
• Value: EC2 public IP Wait for propagation which usually takes a few minutes (can take up to 48 hours).
• After that, domain will point to your server.

Simple Flow:
User enters domain - DNS (Route 53) - resolves to IP - request reaches server.