Backend\Modules\Mailmotor\Installer\Installer::installBackendNavigation PHP Method

    private function installBackendNavigation()
    {
        // settings navigation
        $navigationSettingsId = $this->setNavigation(null, 'Settings');
        $navigationModulesId = $this->setNavigation($navigationSettingsId, 'Modules');
        $this->setNavigation($navigationModulesId, $this->getModule(), 'mailmotor/settings');
    }