The code you entered in the example, G-XXXXXXXXXX , refers to the new Google Analytics 4 which, being a different system from the previous one and does not work (yet) with that plugin.
So you can follow the instructions mentioned in the answer of @Shyam or (and I suggest you because GA4 is too unripe at the moment) create a Universal Analytics type Property and use its ID (UA-XXXXX-X) with the plugin you indicated. You can find it by clicking on Show advanced options (when you create a new property):
