set .conf

[tiger_p]

how i must set .conf file when i use centos7 and iptables to be return just like resualt i want just localhost allowed for using this port for example 35555 and denied every external ip ;

[tiger_p]

localhost allowed to use this port For example 35555
How do I set up a .conf file when I use the iptables script?
becuse I want just localhost allowed to use this port
For example 35555
and Any external IP must be blocked