After Google Analytics updated their analytics system to GA4, all new accounts made come with G- not UA-
When will Shopify support the change?
The Enhanced Ecommerce Shopify integration is only available with UA.
You can add the G- tag code to your theme files if you want to use the GA4 dashboard, or you can still create a UA property during setup (recommended).
I'm trying to outline the options here and will update as new info is released: https://aloagency.com/blog/shopify-and-ga4-analytics-setup
I'm Radi from TAGinstall.
We do have a GA4 implementation in our app Easy Tag - GTM & Data Layer - https://apps.shopify.com/google-tag-manager-installer
Shoot me an email to email@example.com if you need more details.