Question Integrate unity project into flutter

I need to integrate a unity 3d project in to an existing flutter app .Iam using 2021.3.20f1 unity editor and updated flutter version.In pub.dev there is a package Flutter_unity_widget Iam doing everthing of installation instruction but i cannot get the flutter tab in unity editor ( but when i open example project of the package unity show the flutter tab) I think there no updated file in FlutterUnityPackage.unitypackage in the unity packages folder of [github repo] for the 2021.3.20f1 unity editor[https://github.com/juicycleff/flutter-unity-view-widget/tree/master/unitypackages] I need to create the unity project in 2021.3.20f1 unity editor and current version[ 3.7.3] of flutter please provide the step by step insruction if anyone know

 

Same question here

 

I use flutter version 3.7.x does not work, and use fvm change to version 3.0.0 with coresponded dart sdk version and it works