If you have some information you would like to include in your research but it could potentially be distracting to readers or inappropriate within the body of your research paper, you can always include supplemental information as an appendix to your work. An appendix or appendices should always be inserted after your Reference List; however, the appropriateness of appendix content really depends on the nature and scope of your research paper.
For a more in-depth review of what supplemental materials might be included in a social science appendix, be sure to review Section 2.14 “Appendices” (pp. 41-42) of your 7th edition APA manual.
APA 7 addresses appendices and supplemental materials in Section 2.14 and on page 41:
As a general guide, appendices are appropriate for any material that, if presented in the main body of the document, would unnecessarily interrupt the flow of the writing. Note that it is unlikely that you will use appendices in Walden course papers. For doctoral capstone studies, you might include some appendices with supplementary information.