page attributes > page composer

hi,

i’m using the Mansar template for my wordpress site. in the documentation, step 3 says:

03. Homepage Setup

Prepare the page
Go to: Pages → Add New.
Enter the title for this page: Homepage or Home, whatever you like.
On the right side of your screen find the “Page Attributes” box and select “Page Composer” in the “Template” dropdown. Now see the magic happens!

i can’t see the magic happening as there is no such thing as ‘page composer’ under template… only ‘authors list’ and ‘full widht’

have i lost my marbles? any help is appreciated.