Azure Function V3 .Net Core

Hello,
i just upgraded my azure function V1 to V3(Core), I am getting some problem with connection string.
Here is function sample

   [FunctionName("Function1")]  
        public static void Run([IoTHubTrigger("messages/events", Connection = "ConnectionStrings:IoTHubEndpoint")] EventData message, ILogger log)  
        {  
            log.LogInformation($"C# IoT Hub trigger function processed a message: {Encoding.UTF8.GetString(message.EventBody.ToArray())}");  
        }  

I am Getting this error

Here is local.settings.json file.
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "UseDevelopmentStorage=true",
"FUNCTIONS_WORKER_RUNTIME": "dotnet",
},
"ConnectionStrings": {
"IoTHubEndpoint": "mystring"
}
}

Getting this string from here

Someone guide me please what i am doing wrong here ?

Thank you so much for your response.