Django Group permission how to print it in template

def staff_only(view_func):
    def wrapper_function(request, *args, **kwargs):
        group = None
        if request.user.groups.exists():
            group = request.user.groups.all()[0].name
        if group == 'registrar':
            return redirect('adminpage')

        if group == 'admin':
            return view_func(request, *args, **kwargs)
        return redirect("loginpage")

    return wrapper_function

This function is missing case when a user does not have required groups, in this case, either we should either redirect a user to login page send to another page or display like "You don't have access to this page"