APA style was developed by the American Psychological Association. The social sciences often use APA style for documenting sources.
APA 7th edition states that ebooks retrieved from databases (such as EBSCO ebooks, Credo Reference, Ebook Central, Gale Ebooks, etc.) that do not include DOIs do not require a URL in their citation (APA 7th ed, section 10.21). This also applies when citing a chapter from an ebook (APA 7th ed., section 10.39).