This is applicable only to OpenVZ based VPSes. For KVM based VPSes you can configure the whole range on the VPS network interface and use as needed.
Step 1 : Login into CrownPanel (https://crownpanel.com)
Step 2 : Click on "Manage" beside the VPS you wish to manage
Step 3 : Click on the "Manage Network" tab
Step 4 : Click on "Launch" under the IPv6 Wizard
Step 4 : You can add your IPv6 from here