Today, App Runner launched improvements for associating custom domain(s) to an App Runner service in the App Runner console. App Runner makes it easier for developers to quickly deploy containerized web applications and APIs to the cloud, at scale, and without managing infrastructure. When you create an App Runner service, by default, App Runner allocates a domain name to your service. If you have your own domain name, you can associate it to your App Runner service as a custom domain name. With App Runner you do not need to manage TLS/SSL certificates.
Source:: Amazon AWS