var producer = new ProducerBuilderIn the above example, we first create a `ProducerBuilder` object and configure it using various methods, such as `SetValueSerializer` to set the serializer used to serialize message values. We then create a `Producer` object using the `Build` method, and produce a message to the specified topic using `ProduceAsync`. Finally, we call `Flush` with a timeout of 10 seconds to ensure that any buffered messages are sent immediately. Package library: Confluent.Kafka.(config) .SetValueSerializer(new StringSerializer(Encoding.UTF8)) .Build(); producer.ProduceAsync(topic, new Message { Key = "key", Value = "value" }); // flush buffered messages producer.Flush(TimeSpan.FromSeconds(10));