Kafka producer SASL PLAIN Security problems

Question

I have following configs for kafka producer factory:

put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
            put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
            put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
            put("security.protocol", "SASL_PLAINTEXT");
            put("sasl.mechanism", "PLAIN");
            put("sasl.jaas.config", String.format(
                    "org.apache.kafka.common.security.plain.PlainLoginModule required username=\"%s\" password=\"%s\";", KAFKA_USER, KAFKA_PASSWORD));
            put(ProducerConfig.CLIENT_ID_CONFIG, "svc.postsales");

But I am constantly getting errors like this: org.apache.kafka.common.errors.ClusterAuthorizationException: Cluster authorization failed.

But as my devops says and shows on screen he is logged in as producer using my credentials and sent a message to topic.

I tried SCRAM authorization, but it doesn't work: failed authentication due to: Client SASL mechanism 'SCRAM-SHA-256' not enabled in the server, enabled mechanisms are [PLAIN]"}

Can you please help?