Official citation styles for AI are still being created and will likely evolve, but here are some current examples:
APA Style 
in-text citation:

• (OpenAI, 2023)
• reference in bibliography: 
  OpenAI. (2023). ChatGPT (Mar 14 version) [Large language model]. https://chat.openai.com/chat

Chicago Manual of Style

• A parenthetical remark in the text may suffice as an acknowledgement (this text was generated by ChatGPT), but for a more formal citation you can use a footnote:
  1. Text generated by ChatGPT, OpenAI, March 7, 2023, https://chat.openai.com/chat. 
  2. ChatGPT, response to “Explain how to make pizza dough from common household ingredients,” OpenAI, March 7, 2023.

MLA Style

• MLA is more flexible and adaptable, so see their page on citing AI for specifics.
• One possible format: add a parenthetical remark in your text ("Describe the symbolism") to refer to the citation in a "works cited" list:
  "Describe the symbolism of the green light in the book The Great Gatsby by F. Scott Fitzgerald" prompt. ChatGPT, 13 Feb. version, OpenAI, 8 Mar. 2023, chat.openai.com/chat.

Check with your professor about the preferred citation style for your course.

MLA Handbook - Olin Library Reference (Floor 1) Call number: PN203 .G53 2016 
Perhaps the most frequently used citation style in the fields of language and literature. Consult the book for full details, or visit Purdue University's Online Writing Lab.

Chicago Manual of Style Olin Library Reference (Floor 1)  Call number: Z253 .U69 2017
Consult the volume, or access it digitally at the Chicago Manual of Style Online.  Take advantage of the Citation Quick Guide.

Turabian's Manual for Writers of Term Papers, Theses, and Dissertations - Olin Library Reference (Floor 1)  Call number: LB2369 .T8 2017
A somewhat simplified version of the Chicago Manual of Style.