Thank you for your reply, i followed instruction from this link;
https://www.xml-sitemaps.com/howto-install.html. It says i should create blank xml file with notepad which is sitemap.xml and ror.xml but i noticed in the example the files automatically have 228 files each, but the one i created have 0 file. when i tried the [ External links are visible to forum administrators only ] it shows this message; Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@luctrader.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.