Using truemetrics Flutter plugin could be easier. See here more on how it works To use this plugin, just add truemetrics_flutter_sdk as a dependency in your pubspec.yaml file: 
dependencies:
  truemetrics_flutter_sdk: ^0.0.1
Go for the initialize of the SDK 
final sdk = TruemetricsFlutterSdk();
final config = TruemetricsConfig(config: {
    'apiKey': 'your-api-key',
    'debug': true
    });
await sdk.initialize(config);
perform start recording 
await sdk.startRecording();
or Log metadata 
await sdk.logMetadata({'key': 'value'});
and finally stop recording 
await sdk.stopRecording();
and you are done, was easy right :)