How to change a page depending on the UTM tags of this page?

Question

Google

The site page is accessed by links of the form:

http://site.name/index.html?utm_campaign=first
http://site.name/index.html?utm_campaign=second

How to output to <h1></h1>text depending on the UTM tag?

<h1>First</h1>
<h1>Second</h1>

Where to dig?

Answer 1

In your case, utm_campaign is a GET variable, read here www.php.net/manual/ru/reserved.variables.get.php
The algorithm is simple:
1. Check that it is in the request.
2. Depending on the value, set the title.