You may experience an instance when adding an employee to a Team as a manager that you can't see the buttons at the bottom of the window. This will occur if the employee is a manager of a number of Teams.
To proceed, follow the steps below:
Go to Teams and select the one you want to add the user to.
Using the Ellipsis button (three dots), select Add a Member.
Enter the manager's name into Name.
Tick Assign as manager, this will display a caution message.
To move to the next screen, click Tab on your keyboard and then Enter. This should move you to the Remove From page.
Click Enter on the keyboard again. This should move you to the next page, Default Approval Team.
The buttons will be available on this page, so click Done.