In this thread, I will explain to you why you need to have this running for your accounts and how to set it up.
Then on the left-hand side under the Accounts section click "Line of Business".
Then press the blue "Add" button and name it accordingly.
After doing so don't forget to give yourself access to it as well.
Go back to the menu and click on Attribution and then wait a few minutes as Facebook needs time to sync the data
Being able to track cross-device performance and seeing the true attribution across different platforms is invaluable.
Hope you learned something from this thread and please let me know if you have any questions!