Google Analytics Custom Metrics code

My client has sent the following info regarding custom metrics on Google Analytics. I need to add this to x1 page only - can someone confirm if I only need to add the Javascript code - whats the ‘Android SDK’ and ‘iOS SDK’? Also a little confused by the note “Copy the following code snippet for your platform. DO NOT FORGET to replace metricValue with your own.”?

Any help would be much appreciated!

Those are code specific to IOS or Android development (custom apps). You can only add HTML or JavaScript custom code to a Webflow site.

https://support.google.com/analytics/answer/2709828?hl=en

OK, many thanks. So the code snippet they’ve given me is just:

var metricValue = ‘123’;
ga(‘set’, ‘metric1’, metricValue);

Is that all I need? Shouldn’t this have something like “script” around it?

https://www.w3schools.com/js/js_whereto.asp