edit this code:
function is_valid_for_use() {
if (!in_array(get_woocommerce_currency(), array('ARS', 'BRL', 'CLP', 'MXN', 'USD'))) return false;
return true;
}
you have to add your currency code to the array of currencies
find out your currentcy by echoing result from get_woocommerce_currency() and add it to array
It should work!
I had the same problem with Croatian kuna