You should cite AI whenever you quote, summarize, or paraphrase something it generates.
Just like when you cite an author's work, your reader wants to know from where you received that information.
Refer to this post from MLA style's blog to know how to cite AI in MLA style:
Refer to this post from APA style's blog to know how to cite AI in APA style:
650 E Parkway S, Memphis, TN 38104 · (901) 321-3432