Pfoccori ,
Here's a step by step instruction on how to add the script into your site.
Install Head, Footer and Post Injections in your site.
Go to Header and Footer under Settings in the admin dashboard:
Under <HEAD> PAGE SECTION INJECTION, paste the script below:
<script>
FontAwesomeConfig = { autoReplaceSvg: false }
</script>
It should look like this:
After pasting the script, save the changes by clicking on save underneath:
This should now force Font Awesome to not replace the icons with the SVG variant.
After adding this script, your buttons might end up looking like this:
Here are the steps on how to fix this:
Go to the settings page of Buttonizer:
Then go to settings and select Font Awesome 5
Save and publish your changes