If you don't have Uplay Key, Please redeem HERE To redeem your key for Assassin's Creed® Origins, please follow the steps below:
1.Download Uplay PC (you can find it at Uplay.com)
2.Install Uplay PC and log into your account or create a new account
3: Click on Activate Product in the 'Games' section
4: Enter your activation key in the input field and press OK.
5: You can find all your activated games in the GAMES section of the Uplay shop application
6: From here you can download the game and play
7: If you experience a technical problem, we kindly ask you to review the Terms and Conditions of this offer before contacting Ubisoft Technical Support to the following address: https://support.ubi.com
8:The approximate size of the Download game file is 50 GB.
Windows 7 SP1, Windows 8.1, Windows 10 (64-bit versions only)