In an APA in-text citation, you use the phrase “as cited in” if you want to cite a source indirectly (i.e., if you cannot find the original source).
Parenthetical citation: (Brown, 1829, as cited in Mahone, 2018)
Narrative citation: Brown (1829, as cited in Mahone, 2018) states that…
On the reference page, you only include the secondary source (Mahone, 2018).