Wasycwmp wan_device config

i install easycwmp package for openwrt
i run this package and tcp sending on server but WANIPConnection.1.ExternalIPAddress value not sendig
i search in web and find that should edite /usr/share/easycwmp/function/wan_device script
and change interface in functions
but i cant know how edit to get true value
this links write how do this work
please explain for me