functions.cs

[FunctionName("SampleMessageExecutor")]
public static async Task Run(
    [ServiceBusTrigger("test-queue", "test-subscription", Connection = "ServiceBusConnectionString")]
    MessageReceiver messageReceiver, string lockToken)
{
    //the new data is optional
    //you can also use CompleteAsync() or DeadletterAsync()
    await messageReceiver.AbandonAsync(lockToken, new Dictionary<string, object>
    {
        {"new-data", "new-value"}
    });
} 

host.json

{
    "version": "2.0",
    "extensions": {
        "serviceBus": {
            "messageHandlerOptions": {
                "autoComplete": false
            }
        }
    }
}