Users with the Admin role serve as a secondary contact for teams and have many of the same responsibilities as the Account Holder. They can manage certificates, identifiers, profiles, UDIDs, app IDs, and more. They can also add and delete team members and edit user roles, except for the Account Holder.
Users with this role in App Store Connect have access to all apps. They can be internal testers for TestFlight, request promo codes, and more.
For full details on what the Admin role includes, go to Program Roles.
Note: All members of an organization’s team have access to membership resources and benefits. If you’re enrolled as an individual and add users in App Store Connect, users receive access only to App Store Connect and are not considered part of your team in the Apple Developer Program.