I posted here: https://stackoverflow.com/questions/72298875/getting-errors-integrating-amplitude-flutter-package-into-flutter

Here is what I posted:

I used the following reference code from the Amplitude team: https://developers.amplitude.com/docs/flutter-setup]]1]

Here is the relevant portion of my code:

    import 'package:flutter/material.dart';
    import 'package:amplitude_flutter/amplitude.dart';
    import 'package:amplitude_flutter/identify.dart';

    void main() {
      runApp(const MyApp());
    }

    class MyApp extends StatelessWidget {
      const MyApp({Key? key}) : super(key: key);

      // Create the instance
        final Amplitude analytics = Amplitude.getInstance(instanceName: "Assembly");

      // Initialize SDK
        analytics.init(a46xxxxxxxxxxxxxxxx87e);  

       // Log an event
        analytics.logEvent('MyApp startup', eventProperties: {
          'friend_num': 10,
          'is_heavy_user': true
        });

HOWEVER, when running on my local Mac, I get the following errors:

    lib/main.dart:16:5: Error: The name of a constructor must match the name of the enclosing class.
        analytics.init(a46xxxxxxxxxxxxxxxx87e);  
        ^^^^^^^^^
    lib/main.dart:19:24: Error: Expected an identifier, but got ''Assembly''.
    Try inserting an identifier before ''Assembly''.
        analytics.logEvent('Assembly', eventProperties: {
                           ^^^^^^^^^^
    lib/main.dart:19:51: Error: Non-optional parameters can't have a default value.
    Try removing the default value or making the parameter optional.
        analytics.logEvent('Assembly', eventProperties: {
                                                      ^
    lib/main.dart:19:5: Error: The name of a constructor must match the name of the enclosing class.
        analytics.logEvent('Assembly', eventProperties: {
        ^^^^^^^^^
    lib/main.dart:13:43: Error: Method invocation is not a constant expression.
        final Amplitude analytics = Amplitude.getInstance(instanceName: "Assembly");

There were a few inconsistencies in the documentation.

1. Under initialize, it sets it up Amplitude.getInstance().init(a4638276fed4b8ea5c5a9ed13f07987e);

2. But then it says to initialize the following way within the sample code: 

   // Create the instance
       final Amplitude analytics = Amplitude.getInstance(instanceName: "project");
   
   // Initialize SDK
       analytics.init(widget.apiKey);

   It’s unclear to me which is the way to reference the instance (among other things) based on the code example.

1.  

2.   1]: https://developers.amplitude.com/docs/flutter-setup