Same issue here, cannot add the tester channel. When trying to install the app we get "The channel code provided is associated with a channel not available in your region." We are in the UK. Is this tool only for the USA?
I am also unable to add the channel to my French account - no visible error is shown when I try, but from the browser console I see that the URL https://my.roku.com/account/api/v1/channels/accessCode/ZJMQ6D5 is returning a 404 code
It works for me, so it's probably because of your French account. @NB_ doens't seem to participate anymore (and isn't returning my messages), so maybe try https://partnersuccess.roku.com
Thanks! I reached out to Partner Success and it turned out to be a temporary technical problem. It was resolved and I am able to add the test channel now, so it is not in fact restricted to the US.