Hi @Satirdan_kahraman, thanks for taking the time to report this!
(Removing All-and-every-Wikisource as this is not about all and every Wikisource but only about Turkish Wikisource (see its description).)

On English Wikisource, this functionality is provided by a local gadget: https://en.wikisource.org/wiki/MediaWiki:Gadget-PageNumbers-core.js , defined on https://en.wikisource.org/wiki/MediaWiki:Gadgets-definition .
I cannot find any similar gadget on Turkish Wikisource.
In any case, user scripts, gadgets, templates, custom CSS are local on-wiki content. Local content is managed independently on each wiki, by each wiki community themselves.
If you are looking for help with the local code on a wiki, please see https://meta.wikimedia.org/wiki/Small_wiki_toolkits#Ask_your_technical_questions .
This needs changes on the local wiki. Hence I am closing this task here - thanks for your understanding!