Access Security Roles
To access security roles:
Sign in to the Power Platform Admin center as a System Administrator.
In the navigation pane, select Manage.
In the Manage pane, select Environments, and then select an environment from the list.
Select Settings.
Select Users + permissions, and then select Users.
On the Users page select a user, and then select Manage security roles.
Select or deselect security roles. When finished, select Save. After saving, all selected roles become the current assigned roles for the user. Unselected roles aren't assigned.