@Mark T
Thank you for your detailed post!
Since these Access Packages are under Entitlement Management within the Azure Portal, you'll have to reference that category when looking for the GraphAPI commands under Governance.
Here's a full list of the GraphAPI commands for Access Packages under Entitlement Management.
GET https://graph.microsoft.com/beta/identityGovernance/entitlementManagement/accessPackages/{id}
If you have any other questions, please let me know.
Thank you for your time and patience throughout this issue.
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