Warframe

Follow the link warframe.com/user, MANDATORY log out of your account and then log in again(otherwise there may be a Unauthorized Access error). Make sure you are logged into YOUR game account.
Log out of the old twitch account, LOG IN to the new one and ONLY THEN click the button "Link your account!" in the upper right corner of the page. If you dont do this, the old account will be linked automatically.
If for some reason you ignored the product description or accidentally linked an old twitch account, then when you try to link a new one, checkmarks will be shown on Twitch inv, this means that the linking request has been sent and after 7 days after linking previous twitch you will be able to activate this twitch only on that one warframe account where they tried to link it. In this case, you can change all the data on Twitch yourself and wait 7 days if you dont want the seller to wait for you. You dont need mail for this, and items from your new account wont go anywhere.

If twitch asks you for a code from the mail then press "remind later", "cross" or F5 on your keyboard.

MAKE SURE to restart the game, check the receipt of items in the mail and in INVENTORY, since mail is not displayed correctly on some monitor resolutions. In order to view all your mail at once, go to Settings - Video - Screen mode: in window, stretch the game horizontally to half the screen, as shown in the screenshot below, to all mail was displayed.
THE FOLLOWING TEXT ONLY APPLIES TO PRODUCTS WITH MORE THAN 11 FORMAS IN THE DESCRIPTION!!!!! Due to the large number of items in this product, you may need to restart the game several times. You will receive a new mail each time you log in. Even if the second mail only contained a small number of items, log in a few more times to be sure. If you no longer receive mails, the product was received exactly as described.

To unlink Twitch you can go to LINK.
Dont forget that you can get these items again by purchasing a new twitch account, the number of activations per 1 warframe account is not limited, everything is absolutely safe, it's just a twitch linking.