Add 'Terms of Use' after footer copyright in Interface

I want to add a Terms of Use link after the footer copyright information in Interface Theme.

I’ve checked ‘footer.php’. But Interface have this information in ‘footer-extenstions.php’ in the inc/structure directory, that too with some tricky code. I do not have any problem in keeping the links for their websites. But I want to add Terms of Use for my site with a link to a page after this.

Copied below is the code they have in ‘footer-extensions.php’. Please advise.

function interface_footer_info() {
   $output = '<div class="copyright">'.__( 'Copyright &copy;', 'interface' ).' '.interface_the_year().' ' .interface_site_link().' | ' . ' '.__( 'Theme by:', 'interface' ).' '.interface_themehorse_link().' | '.' '.__( 'Powered by:', 'interface' ).' '.interface_wp_link() .'</div><!-- .copyright -->';
   echo $output;
}