Greetings!
Although I am an experienced analytics user (with WordPress), I am struggling to have some things working with Shopify and GA4. I have followed a tutorial from analyzify and managed to have some tags such as view_item working properly but I do not seem to be able to have the purchase_event working.
I am on Shopify basic plan and understand this might be an issue. Nevertheless, it cannot be impossible.
So, my question to you is: If you have managed to have it working properly and you are sending data through the data layer, can you tell me more about your setup?