Thank you PhoneBoy for replying.
I followed : sk132193.
Below steps we did for configuration:
To add external feed: ioc_feeds add --feed_name blocklist --transport https --resource https://xxx.com --user_name admin_account
ioc_feeds show : Gives message that feed is active
file : $FWDIR/external_ioc/feed_name_folder/blocklist_https : Shows the IP address fetched from external feed in format: #UNIQ-NAME,VALUE,TYPE,CONFIDENCE,SEVERITY,PRODUCT,COMMENT
While checking sk103154, it says it is known issue with firewalls behind proxy.
PS: Firewall is standalone and behind proxy. Fw version is : R80.30 - Build 484