def METHOD_NAME(request):
    user = _form_request_user(request)
    user.activate()
    request.session.flash(
        # pylint:disable=consider-using-f-string
        jinja2.Markup(_("User {name} has been activated!".format(name=user.username))),
        "success",
    )
    request.registry.notify(ActivationEvent(request, user))
    return httpexceptions.HTTPFound(
        location=request.route_path(
            "admin.users",
            _query=(("username", user.username), ("authority", user.authority)),
        )
    )