Hi Carman Lawrick, I had the same for a few days, I finally found a solution.
Given you cannot have the context into FlutterFlow, I found a workaround out of Flutter, adding custom Flutter code locally.

I use a global navigator key. Most of topics about it are only about \"MaterialApp()\" and not \"MaterialApp.router()\" (given FF use router), that has made the research a bit complex, I guess you noticed that 😅 ).

Modification to do in the code extracted from FlutterFlow:

In main.dart ->

Pass the navigatorKey to createRouter:
router = createRouter(appStateNotifier, navigatorKey); // Update this line with the navigatorKey as new argument

In nav.dart ->

Update the createRouter function to accept navigatorKey
GoRouter createRouter(AppStateNotifier appStateNotifier, GlobalKey<NavigatorState> navigatorKey) => GoRouter( navigatorKey: navigatorKey, ... ); // add it as an argument define it in the first line

In FlutterFlow or in custom code in your Custom Action, you can now use \"navigatorKey.currentContext?.go('/homePage');\" //homePage is just an example

I hope that will help

push() or go() using GoRouter in custom code?