The ec.js plugin is used in conjunction with analytics.js deployments only. For newer gtag.js deployments, enhanced ecommerce capability is built in and does not require the ec.js plugin.
Do not use the ec.js plugin alongside the older Ecommerce plugin.
The ec.js plugin for analytics.js lets you track the whole arc of your users’ shopping experience, including:
- Viewing product impressions
- Clicking product links
- Viewing product details
- Adding products to, removing products from shopping carts
- Initiating the checkout process
- Completing transactions
- Receiving refunds
Once you've implemented the analytics.js snippet, you can then implement the ec.js plugin.