Now, you may have seen this at the top of your Google Tag Manager:

You might be confused, so what is this new updated Google Tag??
The change is that this Google Tag will replace Google Analytics: GA4 Configuration tag (We don't need you now! RIP!).
What to do on the setup for Google Tag for GA4:
- Tag Id: You have to setup a new Google tag and set the Tag ID. You can find you Tag ID here .
- Setup the configuration setting: You have to either setup a configuration setting variable or define the parameters you need here. Valid parameters can be found here. Suggestion to set "send_page_view" to "true" here.
- Setup Shared Event Settings: This is a really useful function. If you want to pass certain details from the data layer to different events, like a changed page URL, discount code, user information. You can input these specifics in these settings and reuse them in the GA4 tag. Optional for basic setup.
- Trigger: We want to trigger this as soon as possible on all pages. So set it as Initialisation - all pages.
There you have it, a basic new "GA4 Configuration" tag.