Microsoft.Identity.Web - using Access Control List (ACL) based authorization pattern

[HomerBart]

I'm using Azure AD and Microsoft.Identity.Web to protect my .NET 5 web api, however for authorization I need to use my company's custom ACL based system which is based on claims. I've found this Microsoft document on Using ACL-based authorization and I've set the the AllowWebApiToBeAuthorizedByACL to true, however the document doesn't provide any guidance on how add the custom ACL (claims) to the incoming identity/principal so it can be used with the .NET 5 authorization framework. Can anyone provide any guidance on how to do this? Are there any built in classes/interfaces/events in .NET 5 or Microsoft.Identity.Web that I need to use?

Thank you