You get login and password from twitch account for linking to your warframe for gifts (after claiming rewards you can unlink)
1️⃣ Follow the link - https://twitch.amazon.com/prime/loot/warframe
2️⃣ Enter the data from the Twitch account that I gave you.
3️⃣ Log in to your Warframe and link the purchased Twitch account to your Warframe account - https://www.warframe.com/user
4️⃣ Claim reward in twitch.amazon. Exit the game and enter again. Bonuses from Twitch may take up to 24 hours, but usually instant after reogin.
Only for one warframe account, after getting reward becomes useless.
Little guide with screenshots - https://i.imgur.com/L1R8v6K.jpg