This plugin for shopify: https://apps.shopify.com/custom-js
It used to allow you to add a full script tag to the html.
But today a client was complaining saying it did not work for them, when i dug into the issue the plugin appears to have stopped doing that and only allow you to add actual javascript code.
They don't want to use google tag manager, but we need a simple way (that they can understand in the future when i am not there) to be able to inject custom script tags.
EG:
<script src="https://some-review-service.com/loader.js"></script>
Any help would be hugely helpful as I am by no means a shopify guru :)
Use this code in theme.liquid if you are using third party js file:
{{ 'https://some-review-service.com/loader.js' | script_tag }}
Otherwise, upload loader.js file in the assets folder. and add the below code in your theme.liquid head section:
{{ 'loader.js' | asset_url | script_tag }}