To use this layout, create a new post or page by clicking on Posts → Add New Post or Pages → Add New Page in your WordPress backend.
Now, in the right-hand side of the screen you will see a section called Page Attributes. Click on the drop-down list for the Template setting and select the Page without header image template
But the section "Page Attributes" have only Pages adjustment end no have into Post adjustment. How i can remoove big Header in Posts?