I am using .NET Isolated Functions

I need to send multiple messages to a queue

So I am using the code below

[Function("process-duplicates")]
public async Task<DispatchedMessages> ProcessDataAsync([Microsoft.Azure.Functions.Worker.HttpTrigger(AuthorizationLevel.Anonymous,
        "post", Route = "myroute")]
    HttpRequest req,
    IAsyncCollector<string> asyncCollector)
{
    await _passfortDataService.ProcessDataAsync();

    return new DispatchedMessages
    {
        Messages = myService.MessagesToBeSent.Select(x => x.ToJson()),
        Status = new OkObjectResult("Processed Data")
    };
}

Where DispatchedMessages is

public class DispatchedMessages
{
    [JsonIgnore]
    [ServiceBusOutput("QueueName", Connection = "event-bus-connection")]
    public IEnumerable<string> Messages { get; set; }

    public IActionResult Status { get; set; }

}

This works fine for a normal queue

However, I now need to get this work on a session based queue so I need to provide a value for the sessionId

  var messages = new List<ServiceBusMessage>();

  _myServices.MessagesToBeSent.ForEach(x =>
  {
      var message = new ServiceBusMessage(x.ToJson())
      {
        SessionId = "Test"
      };

      messages.Add(message);
    });

    var result = new DispatchedMessages
    {
      Messages = messages.Select(x => x.ToJson()),
      Status = new OkObjectResult("Processed Data")
    };

But this doesnt work

How can I do this?

Paul