DDNS shows 0.0.0.0 or N/A

[musicwizard]

i added freedns.afraid.org to my DDNS.
but when i check the log it says

Nov 8 21:41:00 php-fpm 70807 /services_dyndns_edit.php: Dynamic DNS (…) There was an error trying to determine the public IP for interface - wan (igb0 ).
Nov 8 21:41:00 php-fpm 70807 /services_dyndns_edit.php: Dynamic DNS custom (...): IP address could not be extracted from checkip.dyndns.org

the url checkip.dyndns.org is working in my browser.
did a DNS lookup in pfsense it self to checkip.dyndns.org and it shows 3 ip's

i have a main ISProuter and behind that i have my own PFsense router. so pfsense is getting a 192.168. IP from the ISProuter.