Do you see it here as available to install?
How about if you perform a search for 'gaa' on the Roku device?
I was able to do this on a US based Roku device. Required me to login/create account before I could pair the TV to test the free content under 'Extras' so did not proceed further to check if actually plays.
We’re upgrading Roku Community to bring you a faster, more mobile-friendly experience. You may notice limited functionality or read-only access during this time. Read more here.
Planned Downtime:
Community will be unavailable for up to 24–48 hours during the upgrade window during the week of May 19th and you may notice reduced functionality.
In the meantime, for additional assistance, visit our Support Site.
We're sorry for this disruption — we’re excited to share what’s next!
For support, visit support.roku.com.