To get these items for Deathloop, all you need to do is create a Bethesda.net account and sign up to Arkane Outsiders. Already part of the Arkane Outsiders? Then you only have to log in to the website. There will be confirmation in your transaction history that you have received the items "Deathloop Exclusive Skin and Weapon" - https://bethesda.net/en/account/transaction-history/product-codes
Source: https://bethesda.net/en/article/3SwTPXPaSA47II2A8VWzuY/arkane-outsiders-free-deathloop-items
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