How to make us ADMIN on your Apple Developer Account (via PC/Laptop)
Login to your Apple Store Connect account (http://appstoreconnect.apple.com/login)
Select 'Users and Access'
Click on the developers name that will show as 'App Manager'
The 'Roles' will appear as below
You will need to tick 'ADMIN'
Once you have ticked 'ADMIN' top right click on 'Save'
We will then appear as 'ADMIN' and have access to updating the app