I already have a Pagination on my Post [Single Post Pagination using <!--nextpage--> ] and it looks something like this...

Now, I want to change it to...

I have gone through few documentations and stuff on pages, it's related to wp_link_pages I think... But I can't seem to add this pagination and when ever i try, I break my theme. Honestly at the moment I haven't come up with any codes, I just use what I find on the Internet which implies I am not good with this kind of thing, Obviously I asked question on stackexchange to help me clear this issue. Thank you so much for any kind of help.