macOS Office365 Word

[Andy-L]

I have a word "booklet" (11" x 17" Page size) and following pop-up shows when I try to save as a PDF. File => Print => PDF => Save as PDF Pop-up: The paper size of section 1 is different from the printer page size. The paper size you select on the Page Layout tab and the Printers dialog box (in the Control Panel) must match. Do you want to continue printing?

I want to use "flipbuilder" for the Booklet which requires a PDF input.
Help...