I'm using the API Gateway service to manage my spring boot resources. I want to point the gateway to my sub-domain. I tried adding it to alias in Route 53 but it does not work. There's an option in the API Gateway console which asks for my domain and some credentials. I don't know if a sub-domain can work and what should I add to certificate input. Probably it is asking for an SSL certificate and I am ready to purchase one, but before I do that, I want to be sure that it accepts sub-domains.