In order to add Roku Channels/apps (like the Tixr Play Channel), you need to have a physical Roku streaming device or RokuTV, in order to access the entire Roku platform/environment.
The Roku Channel can be installed on some smart streaming devices (TVs) and you can watch the Roku Channel itself on laptops/computers and other streaming devices (firesticks), but this gives you access only to the Roku Channel, not the entire Roku platform/environment.
In your particular situation, if you are just trying to watch the Anime Expo Lite on your computer, you don't need anything extra like the Roku. Just buy the tickets from their website for the live streaming event and watch it directly on your computer from Tixr. https://lite.anime-expo.org/#faq and https://www.tixr.com/groups/animeexpolite/events/anime-expo-lite-2021-benefitting-hate-is-a-virus-23.... Once you have started streaming it on your computer or laptop, you can use a HDMI cable to your TV if you wish to watch on a larger screen.
If you want to be able to stream directly to your TV instead of computer, you will need to purchase a Roku streaming device in order to install and use the Tixr Play Channel (at least Tixr's Play Channel developed for the Roku).
Hope that helps you.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
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