According to APA, all sources referred to in the text should be retrievable for the reader. But when it comes to what in this context is called "personal communication", such as interviewees or other respondents, anonymity and confidentiality of these persons are prioritized over stating their real names.
Personal communication usually consists of informal sources, such as e-mails, interviews, telephone calls, lectures, lecture notes, and the like. These should therefore not be included as references in the reference list although they are mentioned in the text.
If you use fictitious names, they are placed within quotation marks:
Read more about his on APA Style: Let's Talk About Research Participants