What is the correct way to get only display plugin for Administrator Only

is_admin is true when you’re in the dashboard/admin area, aka example.com/wp-admin. It asks the question “are we in the admin area?”, and is true of anybody logged in and inside the admin area. This could be a user with the role subscriber who sees only the edit profile page. This function is similar to is_home() or is_single(), and has nothing to do with the current user, only their location on the site.

current_user_can( 'manage_options' ) is true, if the current logged in user has the capability with the name manage_options. Normally only administrators have these options. Note that a plugin may change this