Each cluster in appfleet comes with a Global Hostname that you can start using instantly.
But you can also use your own domain to point to your cluster. It can be a top level domain like example.com or any kind of subdomain like www.example.com or api.prod.example.com
Custom domain settings can be found in the settings of each of your clusters.
To configure it you first need to point your domain to your Global Hostname. You will need to go to the control panel of your DNS provider and create a CNAME record pointing to your cluster.
Note: To point root domains like example.com you will have to use an "ANAME" DNS record. Not all DNS providers support them, so make sure your does.
Warning: DO NOT use appfleet IP addresses when configuring your DNS, our IPs change frequently.
Once you create your CNAME or ANAME records make sure you add the domains to your cluster's settings. You can add as many as you need and all changes are applied instantly.