show user-id coverage report in data studio
the UserID is not available in Google Datastudio.
If you really need these values in Google Datastudio you can send the userID as a Custom Dimension using Google Tag Manager. Then you just need to add your new dimensions in your reports as you do with the other dimensions.
Here the instructions to send the userID as a custom dimension https://www.simoahava.com/analytics/improve-data-collection-with-four-custom-dimensions/
I hope this may help you.