How to display tocPages in TOC?

I want to display Article page number in Table of Content right under the Galley (eg: PDF) to display the page number of the article.

I noticed in issue.tpl file there is a line


{$article->getPages()|escape}

I believe that this is the code responsible to achieve what I want. (it is already enabled by default)
But the said item never is shown on the TOC section of the issue.

Do I have to add this pieces of information on the article metadata or galley format or something? because I can not find place to put the page number anywhere. I am using ojs version 2.4.8-2

Please help.
Thank you.