Rejecting a record through topic's Schema

My goal is I want to use Java to produce a record to a topic.
If the record does not match the existing schema on topic, the record should be rejected.

I had follow the steps on the below page and able to produce a record to a topic.
However, there appears to be no schema validation from the topic side.
If I send records not matching the schema that is on the topic, the records still go through.

Is there additional configuration necessary?

https://docs.confluent.io/platform/current/schema-registry/serdes-develop/serdes-json.html#json-schema-serializer

Did you set json.fail.invalid.schema=true?

Keep in mind that topics do not have schemas. Server-side validation is only available in Confluent Server.

The JSONSchemaSerializer on the client-side is what will accept/deny any events from continuing to the topic.