Kubernetes Windows Container GMSA Configuration

I’m working on running a legacy application in windows container. This application uses .NET Framework 4.0 and runs on IIS web server. Also this application requires Windows Authentication. In active directory side, GMSA (group managed service account) configurations are done. Thus, I can run my application with windows authentication in docker container like this:

docker run --security-opt “credentialspec=file://myGMSAConfig.json”

Now, I want to take this a step further, Kubernetes Deployment. I have a kubernetes cluster in Azure and also I have a windows node to deploy my application. I created yaml files and applied to my cluster using

kubectl apply -f myapp.yaml

Here everything is as it should be. But about Windows Authentication I have some problems. I found that I need some configurations to do when I searched for Kubernetes GMSA. I found official documentation in this link. In this documentation I applied every step except the step Enable the WindowsGMSA feature gate but unfortunately it didn’t work. Actually, I think that the documentation is insufficient that’s why I didn’t understand how to do it. Would you help me? I would appreciate any help.

Thanks in advance,
Yours sincerely