Sorry! The Roku streaming player does not provide the ability to browse the internet which is currently required for streaming Rough N' Rowdy. You must be able to access a web browser and http://stream.roughnrowdybrawl.com/.
You can watch the fight on any Google Chrome or Safari compatible device. For a larger viewing option you can mirror your device to your TV with an Apple TV / Chromecast compatible device.
The full list of supported devices include:
Apple products including iPhone and iPads, Android products including phones and tablets / Laptop / Desktop / Apple TV / Chromecast / PS4 (browser) / Xbox One (browser) / 2016 Samsung Tizen Smart TV