advice needed for POD/ Clothing store

I have noticed a very popular product on etsy and other POD sites which is a underwear design with your s/o on the front. Below i attatched the link to what im talking about, ( pictures are banned idk why) . I have a very interesting spin on this idea with a design ready , but i dont know how they custom produce these products. Some people tell me that its exported from china and custom printed and some people say its POD. Does anyone know any sites that can help me further?

https://www.etsy.com/au/search?q=gf%20underwear

interesting, i will get one for my wife