Creating a Group at project level - GraphGroupCreationContext issue

Just want to verify if this API is ready to be consumed and used or this particular one is still at preview?

Looks like the request body and the model doesn't have the same attributes:
In here, there's a displayName and description:
https://docs.microsoft.com/en-us/rest/api/azure/devops/graph/groups/create?view=azure-devops-rest-5.0#create_a_group_at_the_project_level

But on the client, where it asks for a graphgroupcreationcontext, it only asks for a storagekey. And the warning here states that we shouldn't use this for creation of a group:
https://docs.microsoft.com/en-us/rest/api/azure/devops/graph/groups/create?view=azure-devops-rest-5.0#graphgroupcreationcontext

How can I create a group in a project level given the api above?

从 GraphGroupCreationContext 客户端模型开始，并将其与链接的 Azure DevOps REST 项目级组创建文档进行比较。确定该模型与文档记录的请求属性是否一致，并确认创建项目级组的受支持方式。