If you are running a website where you have registered users who are your recurring visitors, you probably want to track their user IDs to know more about their stats. In Order to do this
You can enable the User ID tracking inside the Analytify. Follow these steps to enable it.
Now It’s time to enable the User ID tracking inside the Google Analytics,
In order to do this, login into Google Analytics account and select the website where you want to enable the User ID tracking feature.
After selecting the site where you want to enable the User ID tracking now click on Admin
In next step expand the Tracking Info's sub-menu and click on User-ID
Next step you don't need to do any action, just click on the Next step button
In the next step just click on Create Button to start creating the view to see your User ID tracking.
This is the final step to create your view. Here you can mention your property type Web or Mobile App, and write the name of the reporting view and then click on the Create View.
You have successfully created the view to see User ID tracking. you can see this view by going into admin again and select the User ID View from the Dropdown.
In order to see your User ID tracking data you need to first select the User ID View from the Dropdown and then go to Audience >User Explorer.
Note: Inside the User Explorer, the data will start appearing after 24 hours after creating the view.
in order to map the User ID inside the Google Analytics with your WordPress User ID's and their usernames you can log in into your WordPress Dashboard and go to User's section, inside the users section you can see all the different users you can hover your mouse on the edit button to see their IDs