Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
The only Indieflix Festival I can find any reference to is an app available on the Google Playstore for use on android devices. I can find nothing about them having made it available for Roku.
There IS a listing for Indieflix (not Festival) in the Roku channel store.
What model and model number Roku are you using (Settings > System > About)? I can't find any indication of which Roku models are supported by by Indieflix, but it could be that the channel app requires the capabilities of more recent models than you own.
Likewise, where are you located? Some channels are only authorized in certain countries, although I've been unable to locate information on this re Indieflex.
Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi - Samsung UN55ES6100
Roku Streaming Stick, 3600X, Ser 5S56D8240827, wifi - JVC EM37T