Can I use twitch / Amazon Prime from other countries?

I had the great idea my uncle lives in Germany (me in Austria) to ask if he can lend me his amazon prime. He agreed and I gave him my twitch data so he can link to my twitch account via amazon.
After he did, there was still no twitch prime on my account (it said I could test the free month).
Does it have something to do with my uncle living in Germany and me in Austria?

Maybe it could be because. However, there's a law that enforces an EU wide availability of such services. It's best to get in touch with Amazon support.