enable username and password on kafka bridge strimzi
The HTTP Bridge currently does not support any authentication on the HTTP interface. You can for example combine it with proxy or API Gateway to get that. The authentication which you configured there, is the authentication between the Bridge and the Kafka cluster.
So as a result, the -u user:rghGFDL*%167 in your curl request is ignored. And your connection to Kafka fails because it looks like your broker is not configured for SASL PLAIN authentication (in fact it does nto seem to have any SASL authentication enabled as suggests the Unexpected handshake request with client mechanism PLAIN, enabled mechanisms are [] message).