Route53 conveniently allows you to register and manage domains alongside the rest of your AWS resources. When a domain is registered in Route53, it will automatically have automatic renewal enabled. In the case where automatic renewal is not enabled, Blue Matador will monitor and notify you when the domain is 30 days from expiration.
If your Route53 domain is expiring and you intend to renew it, follow the guide here. To avoid the possibility of a domain expiring accidentally, you can enable automatic renewal on the domain. Avoid waiting until the last minute to renew your domain. Some TLDs disallow renewals as much as 25 days before the expiration date, and it can take a day or more to process a renewal.
Blue Matador also periodically checks if any of the domains represented by your Hosted Zones in Route53 are expiring soon and warns you, even if they do not use AWS as the registrar. To renew your domain with another registrar, contact that registrar.