Use third party Library in wordpress

1. The GA third party library works with php 5.5 and above, i have this.

2. They say to install this via Composer, since i am new to php i have no idea where is it located and will this work on WordPress? Please help me here

Here is Github's url of Third party Library >> https://github.com/theiconic/php-ga-measurement-protocol

3. According to the third party GA Library DOcumentation, i need to add this code to composer:

    {
   "require": {
       "theiconic/php-ga-measurement-protocol": "^2.0"
    }
   }
   

4. After that I need to run this code on Wordpress pages Posts which is related to library

       //We've passed the Google client_id in Calendly's placeholder for utm_term. Feel free to pass it differently, this is just an example
       if(property_exists($objCalendlySubmission-payload-tracking, 'utm_term')  !empty($objCalendlySubmission-payload-tracking-utm_term)) {
           $strPageViewed = 'calendly_conversion.html'; // We use different page names depending on what type of event was scheduled via Calendly
           sendGoogleAnalyticsPageView($objCalendlySubmission-payload-tracking-utm_term, $strPageViewed);
       }
   
       function sendGoogleAnalyticsPageView($strGAClientId, $strURL) {
           require_once '/path_to_composer/composer/vendor/autoload.php'; //loads the PHP library for the "Google Analytics Measurement Protocol”
           $analytics = new TheIconic\Tracking\GoogleAnalytics\Analytics(true); //you may have to adjust this path based on your setup
   
           $analytics
               -setProtocolVersion('1')
               -setTrackingId('YOUR-GA-UA-ID-GOES-HERE')
               -setClientId($strGAClientId)
               -setDocumentLocationUrl($strURL);
   
           $analytics-sendPageview(); //here's where all the effort pays off - this 
           part is simple :)
          }
          ?
   

Please help me implement this code and run this library on wordpress.

Any help will be appreciated