No, you do not need to modify the DNS settings.
Before you use Alibaba Cloud DNS PrivateZone, you must activate the service on the Alibaba Cloud official website. We recommend that you use the default IP address 100.100.2.136 or 100.100.2.138 for your DNS server. After you activate the service, you can add a zone, configure DNS records, and associate the zone with a virtual private cloud (VPC) for which you want to enable the DNS settings.