Se supone que no habra ip block para las regiones centro, como Panama, colombia, argentina etc etc. pero en su pagina dice otra cosa.

I dont understand what you are saying but i take a guess here and tell you that only supported regions are allowed to buy founder packs and play the game.
This is not set by amazon themselves. Smilegate the developer of Lost Ark handed just a list of regions to amazon regarding publishing rights. And this wont change really fast as this takes time to discuss on their end.
All those regions are supported.
You should either buy it from steam, since Panama, colombia, argentina and other are NOT blocked, or, contact customer support from the amazon website
Es muy raro. Si lo intentas comprar directamente desde steam te deja?
is pretty easy to understand him tbh. The post is pretty well worded.
The region is unlocked and they can buy them from steam as of now. But for some reason they cant from amazon? Odd.
Does His Country has an Specific Amazon Site for them?
Eso no es por el juego, es por las compras directamente desde Amazon, es similar a las tarjetas de PS4, si tu cuenta de Amazon esta registrada en Estados Unidos, pero tu tarjeta es de otro país te puede causar problemas, esto pasa con compras digitales. Lo mejor es comprarlo directamente desde steam si no eres de USA. Recuerda que la tienda de Amazon.com es una tienda de Estados Unidos y muchas cosas son vendidas para clientes solamente de dicho país.