That is correct. Contact your instructor to request they convert their content into a format that will play.
Since Adobe no longer supports Flash Player after December 31, 2020 and blocked Flash content from running in Flash Player beginning January 12, 2021, Adobe strongly recommends all users immediately uninstall Flash Player to help protect their systems.
Want to know more? Visit https://www.adobe.com/products/flashplayer/end-of-life.html.