GCN+ app is available in multiple platforms, but for some reason it’s not available on ROKU.
To the best of my knowledge GCN+ is the only way for watching the upcoming Giro d’Italia
You will need to find who is responsible for the app on other platforms and ask if they have or plan to make a Roku app.
It's 'coming soon'. But they have been saying that since I subscribed in February 2021! I doubt it will ever happen.
