We have an external media parnter running programmatic ads for a client. They have a Capture pixel that feeds performance data from the Shopify ecommerce site to their servers. They then include that data within their performance reprots. They've told us they cannot install this pixel on the Shopify site because it's an unusual environment. Our developer also cannot figure out a solution. Have you had experience with this and know how to get that pixel installed? Surely there is a way!
I believe whatever pixel they have is a browser-based tracking script which gets loaded in the browser when a user visits your website.
I don't know what they mean by Shopify site is an unusual environment but if they don't want to meddle with the .liquid files, you can just install Google tag manager unto your website and inject the script from there.
You can have more control like triggering the script based on page URL and user events.
Here is a video by Julian of measure school on how to set up Google tag manager on Shopify. https://www.youtube.com/watch?v=JCVDyiMjS0o
Here is also a resource from Shopify https://help.shopify.com/en/manual/reports-and-analytics/google-analytics/google-tag-manager.
Let me know if you need further assistance. You can reach me on benjamin[at]kudobuzz.com