APA 7th Edition Citation Examples
When to use "p." and "pp."
Use "p." and "pp." when citing book chapters or newspaper articles. Otherwise, page numbers should stand alone; they should not be preceded by "p." or "pp." Follow the examples in this guide.
Online periodical where page numbers are not given
National Geographic, 300(2).
300 is the volume number. Follow the issue number of the magazine or journal with a period.
More info
See Publication Manual, p. 294.