Set the ads campaign display on specific categories

Hello,

I'm using this ads plugin for manage my own ads.

I have asked them about limit the ads campaign running on specific categories here.

They said that I must to use these template tag to integrate it to theme file to make it works.

if(is_category( 'First Category' )){
 do_shortcode("[pro_ad_display_adzone id=1]");
 }elseif( is_category( 'Second Category' )){
 do_shortcode("[pro_ad_display_adzone id=2]");
 }else{
 do_shortcode("[pro_ad_display_adzone id=3]");
 }

I don't know what is the extactly file i need to put it in. Could you use grant access to help me take a look?

Thank you,
Tuan.