如果这些用户在Azure AD中，则可以使用 B2C租户.

If these users are in Azure AD, you can use the Azure AD Integration available for API Management. This is also available for B2C Tenants as well.

如果需要，您还可以将用户注册和产品订阅委派给自己的后端.这里有一个 doc 解释如何设置.

If required, you could also delegate user registration and product subscription to your own backend. Here is a doc explaining how to set this up.

注意:这些功能在基本SKU中不可用.

NOTE: These features are not available in the Basic SKU.