It's still a feature of entitlement management, which requires a P2 License or an Enterprise Mobility + Security E5 License. I tested in my own tenants and noticed that it only worked on the tenant where I had a P2 license applied. https://learn.microsoft.com/en-us/azure/active-directory/governance/entitlement-management-access-package-first
Prerequisites
To use Azure AD entitlement management, you must have one of the following licenses:
Azure AD Premium P2
Enterprise Mobility + Security (EMS) E5 license
I agree that the documentation can be clearer though, as the only prerequisite listed for access package assignment is having the right admin role. I will get the docs updated this week and update this thread once that is done.
https://learn.microsoft.com/en-us/azure/active-directory/governance/entitlement-management-access-package-assignments