Top domain

Hi,

I have a WP installed in a sub domain, would like if is possible to add my top domain ( Prymary ) in some white list…

Example,

in my domain.com i have a download link contain sub.mydomain.com/file.zip
when clicked ( WP No External Links ) do his job end redirect to sub.mydomain.com

My goal is where i could modyfied the code to include my Primary, so when i would click on a download link from my primary domain it will start to download because sub and domain must be in the same rule.

Best regards,

https://wordpress.org/plugins/wp-noexternallinks/