I have a site with many pages and I want to start with Google Ads on it... so I want to insert ads to all the pages, but I want to find a good way... I don't want to add the code manually in all the files... so I tried to build a function to add the google's adsense block after some paragraphs using javascript:

<script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-XXXXXXXX" crossorigin="anonymous"></script>

var display_block = '<ins class="adsbygoogle"' +
        'style="display:block"' +
        'data-ad-client="ca-pub-XXXXX"' +
        'data-ad-slot="xxxxxxxxxx"' +
        'data-ad-format="auto"' +
        'data-full-width-responsive="true"></ins>' +
        '<script>' +
        '(adsbygoogle = window.adsbygoogle || []).push({});' +
        '</script>';

    var afterparagraph1 = document.getElementById('article').getElementsByTagName('p')[0]
    afterparagraph1.insertAdjacentHTML('afterend', display_block );

    var afterparagraph3 = document.getElementById('article').getElementsByTagName('p')[3]
    afterparagraph3.insertAdjacentHTML('afterend', display_block );

Well the code is added (I can see when inspect with console) but the ads doesn´t appear... but if I insert the code manually inside each html file it appears... :(

Do you know what I am doing wrong?

Thanks for your time :)