Hi, like the title says: How exactly it is gotten? Please ping me

You have to purchase an item from a custom wearable shop in new.subeta

https://new.subeta.net/cws/shops

Any item from anyone's shop should work. If you just want the achievement you could wait until this weekend to make a purchase. The CW sale begins on Friday (Dec. 2) where all CWs in shops will be 25% off their normal price.

Yep, I just want it for the cheevie. Thank you, especially for tip about waiting til sale. :)