How do I include a javascript file into the header or footer?

I would like to include:
<script async src="url-here" data-url="url-here"></script>

Am I required to create a plugin or can I edit the source files to include the js file? Either way I am not sure how to achieve this.

The simple way is add it directly to the site on /admin/customize/themes.
Another way is to build a plugin, but you cannot edit the source file. Every change made in those files is overwritten (and deleted) when you update the forum.


Hi @dax Thanks for getting back to me. I was able to achieve this by adding the code into the </head> section :smile: Thanks for the help!