Question Intantiating objects across multiple container pages

I have this script here that generates buttons based on an array and a serialized grid transform

Code (CSharp):

1. public void InitializeUI()
2.         {
3.             LevelItem[] levelItemsArray = LevelSystemManager.Instance.LevelData.levelItemArray;
4.             for (int i = 0; i < levelItemsArray.Length; i++)
5.             {
6.                 if (i % n == 0) // sets it to 15
7.                 {
8.                     LevelButtonScript levelButton = Instantiate(levelBtnPrefab, levelBtnGridHolder);
9.                    levelButton.SetLevelButton(levelItemsArray[i], i, i == LevelSystemManager.Instance.LevelData.lastUnlockedLevel);
10.                     var page = GameObject.FindObjectOfType<UI.Pagination.PagedRect>();
11.                     page.AddPageUsingTemplate();
12.                 }
13.             }
14.         }

Now what I'm trying to do is make that array instantiate a new page (calling the page.AddPageUsingTemplate() function which is from another script) once for every 15 items of the array.

I have 75 levels and want to instantiate the buttons on a new game object which has a grid layout group, so it would be 15 buttons on each grid with 5 pages/grids in total.

I do indeed get 5 pages when I run this code, but since the transform is only set to the first one the buttons don't get placed on the other pages.

How can I place buttons after the first 15 on the following pages?