Global settings
Under Settings > Global settings in the Management console, you can manage Global URLs:
Identity Cloud Instance ID
In these chapters ${instanceId}
refers to the Identity Cloud Instance ID.
When you buy an Identity Cloud subscription, you can select a unique Instance ID that is not already in use.
After the instance you choose is created, you cannot change the Instance ID anymore.

info
You can also request Custom user attributes. For more information, see Custom user attributes.