Pagination Scrolling Effect

[nchowred]

https://projects.lukehaas.me/scrollify/examples/pagination/#second

In this pagination example I was wondering if you could help point me in the right direction on having the active state dot be fixed to the centre of the y axis. When you scroll up/down the sections the dots will be moving along the Y axis. Unsure on how to approach this.

Not sure if I'm explaining it correctly. Here's a gif (refresh to redo it)
https://i.imgur.com/ZbylWyZ.gif

--EDIT--

Found a live website with the example http://www.rcafactory.com/

[nchowred]

Also having troubles implementing the pagination here, I added in the code from pagination example.

I'm getting an error in console
jquery-3.3.1.min.js:formatted:1485 Uncaught TypeError: Cannot read property 'charAt' of undefined at HTMLDivElement.<anonymous> ((index):93) at Function.each (jquery-3.3.1.min.js:formatted:137) at w.fn.init.each (jquery-3.3.1.min.js:formatted:68) at Object.afterRender ((index):88) at i (jquery.scrollify.min.js:1) at Function.j [as scrollify] (jquery.scrollify.min.js:1) at HTMLDocument.<anonymous> ((index):74) at l (jquery-3.3.1.min.js:formatted:1403) at c (jquery-3.3.1.min.js:formatted:1414)

Not sure how to trouble shoot