I am surprised I can not edit my Prezi presentation on Ubuntu, Chromium (Version 71.0.3578.80). I liked Prezi like free and interesting alternative. What is the purpose for this situation on Ubuntu?
Sorry for the inconvenience, currently Ubuntu is not a supported OS but we are going to post an update as soon as this changes.
In the meantime, I can recommend you to However, try running the desktop application or use one of the supported browsers by emulating Windows or by using an application such as Wine.