If the conference that accepted your presentation was canceled, you may list the presentation on your CV under a header such as “Accepted Papers” or “Invited Speeches” and note that the conference did not take place. The following provides an example:
Chen, Joanne. “Strategies for Teaching Grammar to First-Year College Students.” Conference on College Composition and Communication, Milwaukee, WI, 25–28 Mar. 2020. Conference canceled.
If you have an abstract or the paper, you might consider depositing it on a noncommercial repository like the MLA’s Humanities Commons so that you can get a DOI, share your work with colleagues, and invite feedback.