The Managing Editor of the AMA Manual of Style suggests formatting UpToDate topics the same way that you would cite a website:

• Edwards KM, Orenstein WA. Coronavirus disease 2019 (COVID-19): vaccines to prevent SARS-CoV-2 infection. UpToDate. Published December 2020. Updated January 8, 2021.https://www.uptodate.com/contents/coronavirus-disease-2019-covid-19-vaccines-to-prevent-sars-cov-2-infection

Paper Presentation

Pasternak B. Carvedilol vs metoprolol succinate and risk of mortality in patients with heart failure: national cohort study. Paper presented at: European Society of Cardiology Congress; August 31, 2014; Barcelona, Spain.

Poster Presentation

Nevidomskyte D, Meissner MH, Tran N, Murray S, Farrokhi E. Influence of gender on abdominal aortic aneurysm repair in the community. Poster presented at: Vascular Annual Meeting; June 5-7, 2014; Boston, MA.