Delete code added manually years ago

Years ago I made the mistake of adding some Meta Pixel Code to my site artaller.org and I’m almost sure I edited a php file using the cpanel. Today I need to delete that code, but I can’t find where is it located, neither in cpanel files or in any plugin or cornerstone.

<!-- Meta Pixel Code -->
<script>
!function(f,b,e,v,n,t,s)
{if(f.fbq)return;n=f.fbq=function(){n.callMethod?
n.callMethod.apply(n,arguments):n.queue.push(arguments)};
if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';
n.queue=[];t=b.createElement(e);t.async=!0;
t.src=v;s=b.getElementsByTagName(e)[0];
s.parentNode.insertBefore(t,s)}(window, document,'script',
'https://connect.facebook.net/en_US/fbevents.js');
fbq('init', '935470370185126');
fbq('track', 'PageView');
</script>
<noscript><img height="1" width="1" style="display:none"
src="https://www.facebook.com/tr?id=935470370185126&ev=PageView&noscript=1"
/></noscript>
<!-- End Meta Pixel Code -->

I have also the request from my client of moving the following lines frome their current place to the very begining of the code, since apparently that would fix some Google tag manager measurement issues we are having, but I’m not sure if editing directly the code to fulfill my client’s request would bring any significant trouble.

<script type="text/javascript" id="google_gtagjs-js-after">
/* <![CDATA[ */
window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments);}
gtag("set","linker",{"domains":["artaller.org"]});
gtag("js", new Date());
gtag("set", "developer_id.dZTNiMT", true);
gtag("config", "GT-NCG9QB24");
 window._googlesitekit = window._googlesitekit || {}; window._googlesitekit.throttledEvents = []; window._googlesitekit.gtagEvent = (name, data) => { var key = JSON.stringify( { name, data } ); if ( !! window._googlesitekit.throttledEvents[ key ] ) { return; } window._googlesitekit.throttledEvents[ key ] = true; setTimeout( () => { delete window._googlesitekit.throttledEvents[ key ]; }, 5 ); gtag( "event", name, { ...data, event_source: "site-kit" } ); }; 
//# sourceURL=google_gtagjs-js-after
/* ]]> */
</script>