APA does not use footnotes and endnotes for citation purposes. There are two types of explanatory footnotes that APA details use of if necessary: content and copyright.
Content footnotes should be brief and focus on a single subject. They may also direct readers to additional relevant information found elsewhere. For example:
1 See Ramirez (2001), chapter 4, for further analysis of this phenomenon.
Copyright footnotes should not be needed in your Cognella text since we have a dedicated licensing team who will handle all permissions-related content and credit lines for you. Any materials that may warrant permission from the rights holder should be included in your Reading and Excerpts Log. Talk to you project editor if you have questions.
Remember: Every in-text citation should have a corresponding full reference at the end of the chapter in a reference list or bibliography.