I have question regarding integration Google Analytics 4 into Prestashop. My company has setup some years ago Universal Analytics. Now that Google forces everyone to slowly migrate to Google Analytics 4 I was tasked to do it.
I have created GA4 property, inserted gtag into site's code and connected it to the existing UA tag on the site. Everything is working fine, user's data is here except for revenue. Do I need to manually add everywhere custom events as in this documentation? https://developers.google.com/analytics/devguides/collection/ga4/ecommerce?client_type=gtag
I know that they are Prestashop modules for this but they are paid and because of this aren't a option. Also current Google Analytics module don't support GA4
Yes, the url you posted describes ecommerce implementation through gtag. If that's what you're doing, then yes, to get revenue, products, transactions and the rest of EEC-related data, you'll have to implement it as described there.
Most of people choose to implement GA4 through GTM since it's much easier to manage and maintain there. But if the intention is to have tracking with the front-end team, then direct use of gtag may be justified.