You can install the CUX code using Google Tag Manager (GTM). This is the least troublesome and the fastest method to see data in CUX. If your site already has the GTM code implemented you can gather insights in just minutes. Installation via GTM saves you the woes of navigating through the code or admin panel of your site. Once you create a CUX tag and publish your GTM settings the CUX database starts filling with insights.
...
Sign in to Google Tag Manager.
Select the account and container for the site you want to monitor with CUX.
Go to Tags and click New.
Enter a name for the tag. For example, CUX insights.
Click Tag Configuration and select Custom HTML.
Copy the CUX code from your account. Make sure you select the right project if you have more than one.
For more information, see Where can I find the CUX code?Paste your CUX code in the HTML field.
Setup a trigger. Select All pages to ensure the best insight into your visitor behavior. You can optionally add exceptions for pages that you don't want to be monitored with CUX.
Save your new GTM tag configuration.
Use the GTM preview feature to see if the CUX code starts.
a. Click Preview in GTM. It will inform you that the preview mode is on.Image caption: A Google Tag Manager banner showing that preview mode is on.
b. Open your site in a new browser tab.
c. Once a page is loaded GTM opens a panel in at the bottom of the browser window where it shows all scripts that it triggered there. You should be able to see CUX on the list.Image caption: Google Tag Manager preview showing that CUX code has started operating.
Navigate to GTM and switch off the preview mode.
Click Submit to publish the changes.
That’s it! The tracking starts momentarily.Log in to CUX to verify if the code works. See, Checking if the CUX code works
...
Please note, we make sure to have this set of instructions as accurate as possible. It may happen that when Google redesign their tools we may be slightly out of sync. It's always best to check Google's help for the most up-to-date description.
...