How do I cite in APA 7th a source that I don't have directly but see quoted by a source I do have.
Answer
If you have Article A in hand and it quotes Book B and you want to just use that same quote from B (or part of it), APA strongly recommends that you find and read B itself and then cite that directly.
If you're unable to get B and can only see the quote from it through Article A's own quotation from it, then APA's guidance is to do a reference list entry for A and then in the in-text citation identify B and write "as cited in" A.
The manual's example is, when you're quoting a source by Rabbit but only have the source by Lyon and others:
(Rabbit, 1982, as cited in Lyon et al., 2014).
In that example, "only Lyon et al.'s work appears in the reference list."
More on this is on page 258 of the APA 7th edition manual.