Hi @aembytes
The Admin Control option is visible only to the members of the administrators or workflow-administrators group. As you said you are already part of 'Admin' groups by AMS, which will a customized group created by AMS for your organization with few admin privilege such as system console access but it is definitely not part of the other 2 groups which is why you do not see the option.
You can ask AMS to include workflow-administrators into your customized Admin group and you should be able to see it afterwords.
Adobe Link for your reference:
https://experienceleague.adobe.com/docs/experience-manager-65/authoring/essentials/inbox.html?lang=en#inbox-admin-control
Hope this helps!
Thanks!
