ENABLE PAGE BUILDER in SAHIFA

Hello!
I have SAHIFA template for WORDPRESS…
I need to enable PAGE BUILDER in orde to make changes… but i can not find where to find it,…

1. In your page editor, make sure that “Page Builder” button is enabled.???
2. From the Page Builder box you can add the boxes you want to appear in the homepage also you can re-sort the boxes.
3. Each box has its own settings, but some boxes must be added underneath each ohter like in “Category Block | Layout 3”.
4. From the Blocks Settings box you can set the First News Excerpt Length in the news boxes and the posts meta info that appears below posts titles.