Magento 2 Rocket JavaScript extension allows you to enable deferred JavaScript loading and Move JS code to the bottom of the page automatically. That way you increase the website loading speed and eliminate render-blocking.

However, sometimes you don't need to move all JavaScripts to the bottom since there are some that aren't recommended to be moved there.

So, in case you use the deferred JavaScripts on your Magento 2 store page and don't want to move some JavaScript to the bottom you just need to add the attribute data-rocketjavascript="false" to the <script> tag:

Example:

Let's say you had the JavaScript tag like this

<script>
    alert('I do not wont to move this javascript to the footer');
</script>

So, as a result, it will be like:

<script data-rocketjavascript="false" >
    alert('I do not wont to move this javascript to the footer');
</script>