How do you get the Terminator skin in Vanguard?

Excuse me, could you please elaborate on the process of acquiring the Terminator skin in Vanguard? I'm particularly interested in knowing if it's available through gameplay achievements, purchasing from the in-game store, or perhaps as part of a limited-time event. Also, are there any specific requirements or challenges that need to be met in order to unlock this skin? I'd appreciate any detailed information you can provide.