Change Default SMS Flag [Solved]

This is step by step guide to change the default flag in the SMS Field.
In newer version you can change prefix direcly but the flag doesn’t change. Here is how to change de flag:
1) Go to pluging editor and select the plugin.
2) Navigate to “CSS” Folder, the click to open “mailin-front.css”
3) Search for “.sib-cflags” and change the “backgrund-image”:
from
background-image: url(‘../img/flags/fr.png’);
to (for example Argentina is “ar.png”)
background-image: url(‘../img/flags/ar.png’);