How to Add the Load More Button and Pagination to the Posts Block
The Pagination and Load More block is a Premium feature.
You have the the capability to add Pagination and the Load More Button to your Posts block. To do this, all you need to do is to add the Stackable Posts block, and you will see a black plus sign (+) button at the bottom of the block.
Click on the button, and you will find the option to add the Load More button or Pagination. Once you click on it, it will automatically be added to your Posts block, and you have the flexibility to design it any way you want to in the inspector.