Click "Line Spacing" icon shown in the image below. This will allow you to set the correct spacing for the paper.
Choose "Custom Spacing" (the last option on the list)
Custom spacing
⇒ Line spacing: 2 pt
⇒ Paragraph spacing: 0 pt (Before and After)
Type the title of the paper (make sure that it is left-justified (see below).
Then press the Tab button on your keyboard until the cursor moves all the way to the right to left-justify the title, while keeping the page number justified to the right, which meets the APA guidelines for creating a header.
Now you can add automatic pagination by going to the “Insert” tab, clicking on “Page Number” and selecting the correct placement (upper right-hand corner of the document).
All pages in your document will now be consecutively numbered, and your title will be on each page. (Note: It’s okay that the page number is within the 1-inch margin field.)