Step 1: Go to Copilot
Select the playbook where you want to see the contact ID
Step 2: Click on the Column Tool
In the upper right corner
Search “Source system key” and toggle it.

FAQ
Why can’t I do the same at the account level?
At the moment, this feature is only natively applicable for person level, not for account level. If you would like to have account ID displayed in the columns, please refer to this article.