No official Chicago format for citing online classroom materials exists - this is merely a recommended format to use in citing such documents.
3. UMGC, "Week 1 - All About Myth" in HUMN 351 6863 classroom, 2020, http://campus.umgc.edu/.
UMGC. "Week 1 - All About Myth." In HUMN 351 6863 classroom. 2020. http://campus.umgc.edu/.
See the appropriate section depending on the format of the reading:
If in your Discussion post you quote, paraphrase, or summarize your course module or course readings or other material you researched from the library or the Web or a print source, give a footnote citation at the end of your Discussion post in the same manner as you would within a research paper.
If you mention or refer to another student's entry/response in a Discussion post then do not cite it but simply mention the other student's entry in your sentence. Example: I agree with Susan Day (Discussion Post October 30, 2018) where she lists specific state legislatures that supported the Affordable Care Act.