When creating an App Engine application, you may want to use a custom domain name, instead of the generated one at https://[YOUR_PROJECT_ID].appspot.com.
Here is how:
- Buy your domain name at your favorite registar (e.g. domains.google or namesilo.com),
- Head to https://console.cloud.google.com/appengine/settings/domains/add?project=[YOUR_PROJECT_ID],
- Update the DNS records of your custom domain as described in the form,
- By default, you’ll get a free, Google-managed, auto-renewing SSL certificate!