Attach to LTE RAT then DUT supports IPv6 only PS data correctly

Purpose: PS Data after LTE attach is completed [ Ipv6 Home]

Description: Attach to LTE RAT then DUT supports IPv6 only PS data correctly

expected : Device should attach to Ipv6 as primary PS data [ refer IPv6 requirements] Device can also attach to Dual stack IPv4v6

This is a test case and can you help me how can i do this?