Thank you, Shiney.
I've already done using Execute script (JSR-223) after Listerner step.
I get the body, change it to UTF-16, get the values from json and save it to the ParameterList and save it to the Request.
The java code to encode change is:
String utf16 = "";
try {
utf16 = new String(body.getBytes("UTF-16LE"), Charset.forName("UTF-16"));
} catch (UnsupportedEncodingException e){
System.out.println(e);
}
PS: The encode was not windows-1251. It was UTF-16LE.